Method and apparatus for mapping operating parameter in coverage area of wireless network

ABSTRACT

A method for mapping an operating parameter in a coverage area of a wireless network includes obtaining parameter measurements for an operating parameter associated with mobile stations operating in a select portion of a network coverage area for a wireless network, the network coverage area formed by base stations defining cellular coverage areas, the select portion formed by at least one base station, each at least one base station including multiple sector antennas, each sector antenna defining a sector coverage area within the cellular coverage area; and, for each obtained parameter measurement, estimating an instant geographic location of the mobile station in relation to the at least one base station serving the mobile station, each instant geographic location based on a round trip measurement and a signal strength measurement associated with the mobile station, each round trip measurement associated with the serving base station.

BACKGROUND

This disclosure relates to providing wireless service to a mobilestation in a wireless network and more particularly, but notexclusively, to mapping an operating parameter in a coverage area of awireless network.

Geographic location information for mobile stations has tremendous valueto mobile applications, network optimization (e.g., self optimizednetwork (SON)), capacity management, and drive test substitutions, etc.Although many modern mobile stations can obtain their own locations fromintegrated GPS modules, it is still a challenge for the network to trackthe locations of a large number of subscribers for an extended period oftime. A frequent location update from mobile stations would increasenetwork overhead and may overwhelm the network and create bottlenecks. Apassive location estimation technique that leverages measurements fromnormal network operation is desirable because it avoids such increasesin network overhead.

For example, in third generation (3G) code division multiple access(CDMA) networks, such as 3G1X, EVDO, UMTS, etc., one can triangulate thegeographic location of a mobile station from the reported round tripdelays between the mobile station and three or more base stations (seeFIG. 1). The corresponding round trip delays are sent back by the mobilestations for call processing, thus no additional signaling overhead isincurred by the network to collect measurements for triangulation.

However, this triangulation approach does not work in all networks, suchas the fourth generation (4G) long term evolution (LTE) networks. Unlike3G CDMA networks, each measurement report in LTE networks only containsthe round trip delay from one cell (i.e., the serving cell of themobile). Thus, the triangulation technique cannot be used at all inconjunction with 4G LTE networks.

Additionally, geographic location information for mobile stations hastremendous value in compilation and formulation of RF coverage maps forwireless networks. RF coverage maps are useful for management of thenetwork infrastructure and the wireless services provided to users andsubscribers. For example, RF coverage maps may be useful to networkoperators and service providers for troubleshooting and planning formaintenance and upgrades.

However, most of the RF coverage maps are obtained through drive tests.Accurate RF coverage map take hours of drive tests and are very costly.Moreover, as network evolve and environment changes, such as adding newcells or new building construction, the drive tests have to be redone tokeep the coverage information up to date. Thus, maintenance of RFcoverage maps using drive testing adds even more to the cost.

For these and other reasons, there is a need to provide a technique forestimating a geographic location of a mobile station for at least 4G LTEnetworks. Additionally, it is desirable that the technique be compatiblewith other types of wireless networks, especially 3G CDMA networks. Itis also desirable that the technique be more reliable than thetriangulation technique. Additionally, it is desirable that thetechnique for estimating a geographic location of a mobile stationsupport construction or maintenance of RF coverage maps in a more costeffective manner than the drive testing technique. It is also desirableto map other types of parameters collected in conjunction with normaloperation of the wireless network in coverage area maps.

SUMMARY

In one aspect, a method for mapping an operating parameter in a coveragearea of a wireless network is provided. In one embodiment, the methodincludes: obtaining parameter measurements for a select operatingparameter associated with one or more mobile stations operating in atleast a select portion of a network coverage area for a wirelessnetwork, the parameter measurements having been measured during a selectcalendar timeframe, the network coverage area formed by a plurality ofbase stations, each base station defining a cellular coverage areawithin the network coverage area, the select portion of the networkcoverage area formed by at least one base station, each at least onebase station including multiple sector antennas, each sector antennadefining a sector coverage area within the cellular coverage area forthe corresponding base station; and for each obtained parametermeasurement, estimating an instant geographic location of thecorresponding mobile station in relation to the at least one basestation serving the corresponding mobile station, each instantgeographic location based at least in part on a round trip measurementand at least one signal strength measurement associated with thecorresponding mobile station, each round trip measurement associatedwith the at least one base station serving the corresponding mobilestation, each round trip measurement and corresponding at least onesignal strength measurement related in calendar time to thecorresponding parameter measurement.

In another aspect an apparatus for mapping an operating parameter in acoverage area of a wireless network is provided. In one embodiment, themethod includes: an input module and a location module. The input modulefor obtaining parameter measurements for a select operating parameterassociated with one or more mobile stations operating in at least aselect portion of a network coverage area for a wireless network. Theparameter measurements having been measured during a select calendartimeframe. The network coverage area formed by a plurality of basestations. Each base station defining a cellular coverage area within thenetwork coverage area. The select portion of the network coverage areaformed by at least one base station. Each at least one base stationincluding multiple sector antennas. Each sector antenna defining asector coverage area within the cellular coverage area for thecorresponding base station. The location module in operativecommunication with the input module for estimating an instant geographiclocation of the corresponding mobile station for each obtained parametermeasurement in relation to the at least one base station serving thecorresponding mobile station. Each instant geographic location based atleast in part on a round trip measurement and at least one signalstrength measurement associated with the corresponding mobile station.Each round trip measurement associated with the at least one basestation serving the corresponding mobile station. Each round tripmeasurement and corresponding at least one signal strength measurementrelated in calendar time to the corresponding parameter measurement.

In yet another aspect, a non-transitory computer-readable medium storingprogram instructions that, when executed by a computer, cause acorresponding computer-controlled device to perform a method for mappingan operating parameter in a coverage area of a wireless network. In oneembodiment of the non-transitory computer-readable medium, the methodincludes: obtaining parameter measurements for a select operatingparameter associated with one or more mobile stations operating in atleast a select portion of a network coverage area for a wirelessnetwork, the parameter measurements having been measured during a selectcalendar timeframe, the network coverage area formed by a plurality ofbase stations, each base station defining a cellular coverage areawithin the network coverage area, the select portion of the networkcoverage area formed by at least one base station, each at least onebase station including multiple sector antennas, each sector antennadefining a sector coverage area within the cellular coverage area forthe corresponding base station; and for each obtained parametermeasurement, estimating an instant geographic location of thecorresponding mobile station in relation to the at least one basestation serving the corresponding mobile station, each instantgeographic location based at least in part on a round trip measurementand at least one signal strength measurement associated with thecorresponding mobile station, each round trip measurement associatedwith the at least one base station serving the corresponding mobilestation, each round trip measurement and corresponding at least onesignal strength measurement related in calendar time to thecorresponding parameter measurement.

Further scope of the applicability of this the present invention willbecome apparent from the detailed description provided below. It shouldbe understood, however, that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art.

DESCRIPTION OF THE DRAWINGS

The present invention exists in the construction, arrangement, andcombination of the various parts of the device, and steps of the method,whereby the objects contemplated are attained as hereinafter more fullyset forth, specifically pointed out in the claims, and illustrated inthe accompanying drawings in which:

FIG. 1 is a functional diagram showing three cells of a wireless networkin relation to an exemplary embodiment of a triangulation technique forestimating the geographic location of a mobile station;

FIG. 2 is a functional diagram showing a serving cell of a wirelessnetwork in relation to an exemplary embodiment of another technique forestimating the geographic location of a mobile station;

FIG. 3 is a graph showing a transmit antenna gain characteristic for asector antenna of a base station in which normalized gain in dB isplotted in relation to look angles from the sector antenna to a mobilestation in relation to azimuth (i.e., horizontal gain) and elevation(i.e., vertical gain) positions from the orientation of the sectorantenna;

FIG. 4 is a flow chart of an exemplary embodiment of a process forestimating a geographic location of a mobile station within a coveragearea of a wireless network;

FIG. 5, in combination with FIG. 4, is a flow chart of another exemplaryembodiment of a process for estimating a geographic location of a mobilestation within a coverage area of a wireless network;

FIG. 6 is a block diagram of an exemplary embodiment of an apparatuswithin a serving base station of a wireless network for estimating ageographic location of a mobile station within a coverage area of thewireless network;

FIG. 7 is a block diagram of an exemplary embodiment of an apparatuswithin a geo-location service node of a wireless network for estimatinga geographic location of a mobile station within a coverage area of thewireless network;

FIG. 8 is a block diagram of an exemplary embodiment of an apparatuswithin a network management node associated with a wireless network forestimating a geographic location of a mobile station within a coveragearea of the wireless network;

FIG. 9 is a block diagram of an exemplary embodiment of an angularposition module associated with the apparatus shown in FIGS. 6-8;

FIG. 10 is a flow chart of an exemplary embodiment of a process forestimating a geographic location of a mobile station within a coveragearea of a wireless network performed by a computer-controlled deviceexecuting program instructions stored on a non-transitorycomputer-readable medium;

FIG. 11 is a bird's eye view of a coverage area of an exemplary basestation in a wireless network showing an estimated geographic locationand a GPS location for a mobile station;

FIG. 12 is a set of graphs showing azimuth gain parametercharacteristics for two sector antennas of a base station, elevationgain parameter characteristics for the two sector antennas, a compositegraph showing the difference between gains for the two sector antennas,and a graph of a function of the angular position of the mobile stationin relation to the delta antenna gain component, a delta transmitparameter component, and a delta signal strength measurement component;

FIG. 13 is a functional diagram showing three base stations, each withthree sector antennas, in relation to exemplary embodiments of varioustechniques for estimating the geographic location of a mobile station;

FIG. 14 is an example of an RF coverage map for a sector antenna of abase station that is used in relation to an exemplary embodiment of atechnique for estimating the geographic location of a mobile station;

FIG. 15 is another example of an RF coverage map for a sector antenna ofa base station that is updated in conjunction with an exemplaryembodiment of a technique for estimating the geographic location of amobile station;

FIG. 16 is yet another example of an RF coverage map for a sectorantenna of a base station that is used in relation to another exemplaryembodiment of a technique for estimating the geographic location of amobile station;

FIG. 17 is a flow chart of an exemplary embodiment of a process forestimating a geographic location of a mobile station within a coveragearea of a wireless network;

FIG. 18, in combination with FIG. 17, is a flow chart of anotherexemplary embodiment of a process for estimating a geographic locationof a mobile station within a coverage area of a wireless network;

FIG. 19, in combination with FIG. 17, is a flow chart of yet anotherexemplary embodiment of a process for estimating a geographic locationof a mobile station within a coverage area of a wireless network;

FIG. 20 is a flow chart of still another exemplary embodiment of aprocess for estimating a geographic location of a mobile station withina coverage area of a wireless network;

FIG. 21, in combination with FIG. 20, is a flow chart of still yetanother exemplary embodiment of a process for estimating a geographiclocation of a mobile station within a coverage area of a wirelessnetwork;

FIG. 22, in combination with FIG. 20, is a flow chart of anotherexemplary embodiment of a process for estimating a geographic locationof a mobile station within a coverage area of a wireless network;

FIG. 23 is a flow chart of yet another exemplary embodiment of a processfor estimating a geographic location of a mobile station within acoverage area of a wireless network;

FIG. 24 is an exemplary set of signaling usage maps for a cluster ofcellular coverage areas for a wireless network showing six 1-hoursamples of signaling usage over a 24-hour period;

FIG. 25 is an exemplary set of data usage maps showing a map for alldevices in the cluster of cellular coverage areas and maps for certaintypes of devices during a 1-hour sample of data usage;

FIG. 26 is an exemplary set of signaling usage maps showing a map forall devices in the cluster of cellular coverage areas and maps forcertain types of devices during a 1-hour sample of signaling usage;

FIG. 27 is an exemplary set of population maps showing a map for allactive devices in the cluster of cellular coverage areas and maps forcertain types of devices during a 1-hour sample of active devices;

FIG. 28 is a flow chart of an exemplary embodiment of a process formapping an operating parameter in a coverage area of a wireless network;

FIG. 29, in combination with FIG. 28, is a flow chart of anotherexemplary embodiment of a process for mapping an operating parameter ina coverage area of a wireless network;

FIG. 30, in combination with FIG. 28, is a flow chart of yet anotherexemplary embodiment of a process for mapping an operating parameter ina coverage area of a wireless network;

FIG. 31, in combination with FIGS. 28 and 30, is a flow chart of afurther exemplary embodiment of a process for mapping an operatingparameter in a coverage area of a wireless network;

FIG. 32, in combination with FIGS. 28 and 30, is a flow chart of anotherfurther exemplary embodiment of a process for mapping an operatingparameter in a coverage area of a wireless network;

FIG. 33 is a block diagram of an exemplary embodiment of an apparatuswithin a network management node associated with a wireless network formapping an operating parameter in a coverage area of the wirelessnetwork; and

FIG. 34 is a flow chart of an exemplary embodiment of a process formapping an operating parameter in a coverage area of a wireless networkperformed by a computer-controlled device executing program instructionsstored on a non-transitory computer-readable medium.

DETAILED DESCRIPTION

Various embodiments of methods and apparatus provide techniques formapping an operating parameter in a coverage area of a wireless network.In one embodiment, parameter measurements associated with operation of amobile station in a coverage area of a base station having multiplesector antennas are obtained for a select operating parameter, obtaininga round trip measurement and at least one signal strength measurementassociated with the mobile station, estimating the instant geographiclocation of the mobile station based at least in part on the round tripmeasurement and the at least one signal strength measurement to relateinstant geographic locations with each parameter measurement. Varioustechniques for processing and mapping the parameter measurements incoverage area maps based at least in part on the estimated geographiclocations are also presented. For example, any suitable operatingparameter that is measured in conjunction normal operations of mobilestations in the wireless network can be mapped, such as signal strengthmeasurements in RF coverage maps, data or signaling usage forcommunication sessions in usage maps, device or application usage inpopulation maps, and throughput, packet loss, or packet delay in qualityof service maps. The various embodiments described herein provideimproved accuracy of information in location estimates for mobilestations by combining measurements for both the distance and signalingstrength/quality reports in the algorithm for estimating the location.

The estimating of the geographic location of mobile stations inconjunction with mapping parameter measurements can be accomplishedusing any of the various embodiments of methods and apparatus forestimating a geographic location of a mobile station described below inthe descriptions of FIGS. 1-27. Depending on the operating parameter,maps can be generated to indicate network performance, coverage, usage,and end user experience or activities. The maps are generated based onreal user information. Actual users can be indoors or outdoors, can bein fast moving vehicle or stationary. Conversely, for measurementsobtained from drive test data, the drive test device is normally in amoving vehicle in an outdoor environment to which the vehicle hasaccess. Metrics of interest, such as coverage, usage, user experienceand activities, etc can be tracked for all active users during anyselect calendar time. In fact, tracking could be continuous using arolling time window. Limitations on calendar time for tracking or thesize of the rolling time window may arise if limitations on storagecapacity are encountered. On the other hand, drive test data can only becollected in conjunction with scheduled drive tests that are usually setup for a certain time of the day and is one time event. Drive test datacannot reflect network operation conditions 24 hours a day, seven days aweek.

The various embodiments of methods and apparatus for estimating ageographic location of a mobile station described below in thedescriptions of FIGS. 1-27 can be used to estimate the geographiclocation of mobile stations in conjunction with the measurement ofoperating parameters to be mapped. The operating parameters can beselected so that the maps indicate network performance, coverage, usageand end user experience. These maps can be used for optimizing thewireless network (SON), troubleshooting, network planning, etc.

The various types of coverage area maps include RF coverage maps, usagemaps, population maps, user experience maps, and user profile maps. RFcoverage maps can provide RF coverage map for a given cell, a givensector of a cell, or a cluster of cells. If multiple sector antennas ofa base station cover a given sub-sector area of the map, the sectorantenna providing the strongest coverage may be mapped. RF coverage mapsthat show call drop locations and handoff zones can be generated.

Usage maps can be generated for all active devices or by device type,device model, and software application in various combinations. Usagemaps can show data usage or signaling usage for communication sessions.Population maps can also be generated for all active devices or bydevice type, device model, or software applications in variouscombinations. For example, population maps plot the number of activedevices for a given device model, such as the number of iPhones activein a 50 meter by 50 meter sub-sector geographic area (i.e., geo-binarea). User experience maps can be generated for all active devices orby device type, device model, or software application in variouscombinations. User experience maps plot metrics (i.e., parametermeasurements) reflecting quality of service, such as throughput, packetloss, or packet delay. For example, a throughput map for a YouTubesoftware application or a packet loss map for a Blackberry device. Userprofile maps may be generated per geographic location or geographicarea. For example, user profile maps can show software applicationsused, web sites visited, etc.

With reference to FIG. 24, an exemplary set of signaling usage maps fora cluster of cellular coverage areas for a wireless network shows six1-hour samples of signaling usage over a 24-hour period. An exemplaryembodiment of a process for generating data usage maps during differenthours of the day includes dividing an area of interest into sub-sectorgeographic areas (i.e., geo-bins). For example, a geo-bin size canrepresent a 50 meter by 50 meter sub-sector geographic area within thecoverage area of a wireless network or a portion thereof. For a givencall record during the given hour, the process includes estimating themobile station location by using any suitable embodiment of thenetwork-based geo-location method discussed below in the descriptions ofFIGS. 1-27. The mapping process also includes extracting data usageinformation from the call record and storing the usage amount in thecorresponding geo-bin for the given hour. The data usage information inthe geo-bin can be processed to determine a representative usage valueto be mapped in the sub-sector geographic area of the coverage area map.

With reference to FIG. 25, an exemplary set of data usage maps shows amap for all devices in the cluster of cellular coverage areas and mapsfor certain types of devices during a 1-hour sample of data usage.Similarly, FIG. 26 shows an exemplary set of signaling usage maps,including a map for all devices in the cluster of cellular coverageareas and maps for certain types of devices during a 1-hour sample ofsignaling usage. FIG. 27 shows an exemplary set of population maps,including a map for all active devices in the cluster of cellularcoverage areas and maps for certain types of devices during a 1-hoursample of active devices.

With reference to FIG. 28, an exemplary embodiment of a process 2800 formapping an operating parameter in a coverage area of a wireless networkbegins at 2802 where parameter measurements for a select operatingparameter associated with one or more mobile stations operating in atleast a select portion of a network coverage area for a wireless networkare obtained. The parameter measurements having been measured during aselect calendar timeframe. The network coverage area formed by aplurality of base stations. Each base station defining a cellularcoverage area within the network coverage area. The select portion ofthe network coverage area formed by at least one base station. Each atleast one base station including multiple sector antennas. Each sectorantenna defining a sector coverage area within the cellular coveragearea for the corresponding base station. At 2804, for each obtainedparameter measurement, an instant geographic location of thecorresponding mobile station is estimated in relation to the at leastone base station serving the corresponding mobile station. Each instantgeographic location based at least in part on a round trip measurementand at least one signal strength measurement associated with thecorresponding mobile station. Each round trip measurement associatedwith the at least one base station serving the corresponding mobilestation. Each round trip measurement and corresponding at least onesignal strength measurement related in calendar time to thecorresponding parameter measurement.

With reference to FIGS. 28 and 29, another exemplary embodiment of aprocess 2900 for mapping an operating parameter in a coverage area of awireless network includes the process 2800 of FIG. 28 and continues with2902 where obtained parameter measurements for each instant geographiclocation are processed to obtain a representative parameter value forthe corresponding instant geographic location. At 2904, a coverage areamap for the wireless network is populated with the representativeparameter values based at least in part on the instant geographiclocation associated with the corresponding representative parametervalue. The coverage area map including at least the select portion ofthe network coverage area.

In another embodiment of the process 2900, the representative parametervalues are obtained by filtering the corresponding parametermeasurements to remove unreliable measurements, averaging thecorresponding parameter measurements, determining a median value for thecorresponding parameter measurements, selecting a preferred parametermeasurement from the corresponding parameter measurements based at leastin part on a preferred calendar time for the correspondingrepresentative parameter value, any other suitable processing technique,or any suitable combination thereof.

In yet another embodiment of the process 2900, the coverage area map isan RF coverage area map, a handoff zone coverage area map, a data usagecoverage area map, a signaling usage coverage area map, a populationcoverage area map for directory number identification, deviceidentification, device type, or application program, a quality ofservice coverage area map for throughput, packet loss, or packet delay,a user profile coverage area map, any other suitable coverage area map,or any suitable combination thereof.

With reference to FIGS. 28 and 30, yet another exemplary embodiment of aprocess 3000 for mapping an operating parameter in a coverage area of awireless network includes the process 2800 of FIG. 28. In thisembodiment, at least the select portion of the network coverage area isrepresented in a coverage area map for the wireless network by aplurality of sub-sector geographic areas. Each sub-sector geographicarea uniquely identified and associated with at least a portion of thesector coverage area for at least one sector antenna. At 3002, eachestimated instant geographic location is correlated with a sub-sectorgeographic area of the plurality of sub-sector geographic areas. Eachsub-sector geographic area adapted to represent more than one instantgeographic location. The correlating based at least in part on areference location in the coverage area map for the at least one basestation serving the mobile station associated with the correspondinginstant geographic location.

With reference to FIGS. 28, 30, and 31, a further exemplary embodimentof a process 3100 for mapping an operating parameter in a coverage areaof a wireless network includes the processes 2800, 3000 of FIGS. 28 and30 and continues with 3102 where obtained parameter measurements foreach sub-sector geographic area are processed to obtain a representativeparameter value for the corresponding sub-sector geographic area. At3104, the coverage area map is populated with the representativeparameter values based at least in part on the sub-sector geographicarea associated with the corresponding representative parameter value.

With reference to FIGS. 28, 30, and 32, another further exemplaryembodiment of a process 3200 for mapping an operating parameter in acoverage area of a wireless network includes the processes 2800, 3000 ofFIGS. 28 and 30. In this embodiment, each sub-sector geographic area isassociated with a corresponding geographic location bin for storage ofparameter measurements associated with the instant geographic locationsrepresented by the corresponding sub-sector geographic. At 3202, eachobtained parameter measurement is stored in a geographic location binassociated with the sub-sector geographic area representing the instantgeographic location associated with the corresponding parametermeasurement. Next, the parameter measurements stored in each geographiclocation bin is processed to obtain a representative parameter value forthe corresponding geographic location bin (3204). At 3206, the coveragearea map is populated with the representative parameter values based atleast in part on the geographic location bin associated with thecorresponding representative parameter value and the sub-sectorgeographic area associated with the corresponding geographic locationbin.

With reference again to FIG. 28, in another embodiment of the process2800, the parameter measurements are obtained from call records,subscriber records, service provider records, other suitable types ofwireless data records, or any suitable combination thereof. The recordsmay include data that is captured and/or maintained during normaloperation of the wireless network that provide wireless services tomobile stations. The records may also include data that supportsaccounting and billing functions for the service provider.

In yet another embodiment of the process 2800, the select operatingparameter includes one or more of a signal strength parameter associatedwith RF signals received by mobile stations from sector antennas, ahandoff parameter associated with handoffs of mobile stations fromserving sector antennas to neighboring sector antennas of serving basestations or neighboring base stations, a data usage parameter associatedwith data usage during call sessions to and from mobile stations, asignaling usage parameter associated with setup and teardown of callsessions to and from mobile stations, a directory number identificationparameter associated with telephone numbers for mobile stations, adevice identification parameter associated with serial numbers of mobilestations, a device type parameter associated with categorizing mobilestations into different types by manufacturer, model, or technicalfeature, an application identification parameter associated withapplication programs used by mobile stations, a throughput parameterassociated with call sessions for mobile stations, a packet lossparameter associated with call sessions for mobile stations, a packetdelay parameter associated with call sessions for mobile stations, auser profile parameter associated with observed behavior or preferencesof users of mobile stations, or any other suitable operating parameter.

In still another embodiment of the process 2800, the select portion ofthe network coverage area is formed by at least two base stations. Inthe embodiment being described, each at least two base stationsincluding multiple sector antennas. In still yet another embodiment ofthe process 2800, at least some instant geographic locations are basedat least in part on the round trip measurement and first and secondsignal strength measurements of the at least one signal strengthmeasurement. In this embodiment, the first and second signal strengthmeasurements being from different sector antennas.

In another embodiment of the process 2800, at least some instantgeographic locations are based at least in part on the round tripmeasurement, a first signal strength measurement of the at least onesignal strength measurement, and a first RF coverage map for a firstsector antenna serving the mobile station associated with the round tripmeasurement and with which the first signal strength measurement isassociated. In a further embodiment of the process 2800, one or moreinstant geographic locations are also based at least in part on a secondsignal strength measurement of the at least one signal strengthmeasurement and a second RF coverage map for a second sector antennawith which the second signal strength measurement is associated, thesecond sector antenna associated with a neighboring base station inrelation to the base station serving the mobile station.

In yet another embodiment of the process 2800, parameter measurementsare obtained and the instant geographic locations are estimated inresponse to detection of a dropped call for the one or more mobilestations.

With reference to FIG. 33, an exemplary embodiment of an apparatus formapping an operating parameter in a coverage area of the wirelessnetwork includes an input module 3300 and a location module 3302. Theinput module 3300 for obtaining parameter measurements for a selectoperating parameter associated with one or more mobile stationsoperating in at least a select portion of a network coverage area for awireless network. The input module 3300 may obtain the parametermeasurements from the components of the wireless network, an operationand maintenance (OAM) system, a charging system, a billing system, orany suitable combination thereof. The parameter measurements having beenmeasured during a select calendar timeframe. The network coverage areaformed by a plurality of base stations. Each base station defining acellular coverage area within the network coverage area. The selectportion of the network coverage area formed by at least one basestation. Each at least one base station including multiple sectorantennas. Each sector antenna defining a sector coverage area within thecellular coverage area for the corresponding base station.

The location module 3302 in operative communication with the inputmodule 3300 for estimating an instant geographic location of thecorresponding mobile station for each obtained parameter measurement inrelation to the at least one base station serving the correspondingmobile station. Each instant geographic location based at least in parton a round trip measurement and at least one signal strength measurementassociated with the corresponding mobile station. The round trip and theat least one signal strength measurement obtained via the input module3300. The input module 3300 may obtain the round trip measurements andsignal strength measurements from the components of the wirelessnetwork, OAM system, charging system, billing system, or any suitablecombination thereof. Each round trip measurement associated with the atleast one base station serving the corresponding mobile station, eachround trip measurement and corresponding at least one signal strengthmeasurement related in calendar time to the corresponding parametermeasurement.

In the embodiment being described, the apparatus may include a networkmanagement node 3304 associated with the wireless network and inoperative communication with wireless network storage node(s) 3306, OAMstorage node(s) 3308, charging system storage node(s) 3310, and billingsystem storage nodes(s) 3312 to obtain parameter measurements foroperating parameters associated with mobile stations, including roundtrip measurements and signal strength measurements from call records3314, subscriber records 3316, service provider records 3318, or anysuitable combination thereof. The network management node 3304 is inoperative communication with a network operator terminal 3320 tofacilitate management of the infrastructure for the core wirelessnetwork by the network operator. The network management node 3304 isalso in operative communication with a wireless service providerterminal 3322 to facilitate management of a service provided tosubscribers via the core wireless network by the provider of thewireless service.

In another embodiment, the network management node 3304 may also includea processing module 3324 and a mapping module 3326. The processingmodule 3324 in operative communication with the input module 3300 andlocation module 3302 for processing the obtained parameter measurementsfor each instant geographic location to obtain a representativeparameter value for the corresponding instant geographic location. Themapping module 3326 in operative communication with the processingmodule 3324 for populating a coverage area map for the wireless networkwith the representative parameter values based at least in part on theinstant geographic location associated with the correspondingrepresentative parameter value, the coverage area map including at leastthe select portion of the network coverage area. The network managementnode 3304 may make coverage area maps accessible to authorized networkoperators via the network operator terminal 3320 and/or accessible toauthorized wireless service providers via the wireless service providerterminal 3322. For example, the coverage area maps may be communicatedto the network operator terminal 3320 and/or wireless service providerterminal 3322 via the mapping module 3326 in as an image of the coveragearea map or as data reflecting the representative parameter values,instant geographic locations, and other map information in a formsuitable for the corresponding terminal to construct the image of thecoverage area map.

In a further embodiment of the network management node 3304, theprocessing module 3324 obtains the representative parameter values byone or more of filtering the corresponding parameter measurements toremove unreliable measurements, averaging the corresponding parametermeasurements, determining a median value for the corresponding parametermeasurements, selecting a preferred parameter measurement from thecorresponding parameter measurements based at least in part on apreferred calendar time for the corresponding representative parametervalue, any other suitable processing technique, or any suitablecombination thereof.

In an alternate further embodiment of the network management node 3304,the coverage area map is an RF coverage area map, a handoff zonecoverage area map, a data usage coverage area map, a signaling usagecoverage area map, a population coverage area map for directory numberidentification, device identification, device type, or applicationprogram, a quality of service coverage area map for throughput, packetloss, or packet delay, a user profile coverage area map, any othersuitable coverage area map, or any suitable combination thereof.

In yet another embodiment of the network management node 3304, at leastthe select portion of the network coverage area is represented in acoverage area map for the wireless network by a plurality of sub-sectorgeographic areas. Each sub-sector geographic area uniquely identifiedand associated with at least a portion of the sector coverage area forat least one sector antenna. In this embodiment, the network managementnode 3304 also includes a correlation module 3328 in operativecommunication with the location module 3302 for correlating eachestimated instant geographic location with a sub-sector geographic areaof the plurality of sub-sector geographic areas. Each sub-sectorgeographic area adapted to represent more than one instant geographiclocation. The correlating based at least in part on a reference locationin the coverage area map for the at least one base station serving themobile station associated with the corresponding instant geographiclocation.

In a further embodiment, the network management node 3304 also includesthe processing module 3324 and mapping module 3326. In this embodiment,the processing module 3324 is in operative communication with the inputmodule 3300 and correlating module 3328 for processing the obtainedparameter measurements for each sub-sector geographic area to obtain arepresentative parameter value for the corresponding sub-sectorgeographic area. In the embodiment being described, the mapping module3326 is in operative communication with the processing module 3324 forpopulating the coverage area map with the representative parametervalues based at least in part on the sub-sector geographic areaassociated with the corresponding representative parameter value.

In an alternate further embodiment of the network management node 3304,each sub-sector geographic area is associated with a correspondinggeographic location bin for storage of parameter measurements associatedwith the instant geographic locations represented by the correspondingsub-sector geographic. In this embodiment, the network management node3304 also includes a storage device 3330, processing module 3324, andmapping module 3326. The storage device 3330 in operative communicationwith the input module 3300 and the location module 3302 for storing eachobtained parameter measurement in a geographic location bin associatedwith the sub-sector geographic area representing the instant geographiclocation associated with the corresponding parameter measurement. Thestorage device 3330 also stores the round trip and signal strengthmeasurements used by the location module 3302. In this embodiment, theprocessing module 3324 is in operative communication with the storagedevice 3330 and correlating module 3328 for processing the parametermeasurements stored in each geographic location bin to obtain arepresentative parameter value for the corresponding geographic locationbin. In the embodiment being described, the mapping module 3326 is inoperative communication with the processing module 3324 for populatingthe coverage area map with the representative parameter values based atleast in part on the geographic location bin associated with thecorresponding representative parameter value and the sub-sectorgeographic area associated with the corresponding geographic locationbin.

In still another embodiment of the network management node 3304, theinput module 3300 obtains the parameter measurements from call records3314, subscriber records 3316, and service provider records 3318captured or maintained during normal operation of the wireless networkthat provide wireless services to mobile stations or that supportaccounting and billing functions for the service provider. The callrecords 3314, subscriber records 3316, and service provider records 3318may be obtained from storage in the wireless network storage node(s)3306, OAM storage node(s) 3308, charging system storage node(s) 3310,billing system storage node(s) 3312, or any suitable combinationthereof.

In still yet another embodiment of the network management node 3304, theselect operating parameter includes one or more of a signal strengthparameter associated with RF signals received by mobile stations fromsector antennas, a handoff parameter associated with handoffs of mobilestations from serving sector antennas to neighboring sector antennas ofserving base stations or neighboring base stations, a data usageparameter associated with data usage during call sessions to and frommobile stations, a signaling usage parameter associated with setup andteardown of call sessions to and from mobile stations, a directorynumber identification parameter associated with telephone numbers formobile stations, a device identification parameter associated withserial numbers of mobile stations, a device type parameter associatedwith categorizing mobile stations into different types by manufacturer,model, or technical feature, an application identification parameterassociated with application programs used by mobile stations, athroughput parameter associated with call sessions for mobile stations,a packet loss parameter associated with call sessions for mobilestations, a packet delay parameter associated with call sessions formobile stations, a user profile parameter associated with observedbehavior or preferences of users of mobile stations, or any othersuitable operating parameter.

In another embodiment of the network management node 3304, the selectportion of the network coverage area is formed by at least two basestations. In the embodiment being described, each at least two basestations including multiple sector antennas. In yet another embodimentof the network management node 3304, at least some instant geographiclocations estimated by the location module 3302 are based at least inpart on the round trip measurement and first and second signal strengthmeasurements of the at least one signal strength measurement. In thisembodiment, the first and second signal strength measurements being fromdifferent sector antennas.

In still another embodiment of the network management node 3304, atleast some instant geographic locations estimated by the location module3302 are based at least in part on the round trip measurement, a firstsignal strength measurement of the at least one signal strengthmeasurement, and a first RF coverage map for a first sector antennaserving the mobile station associated with the round trip measurementand with which the first signal strength measurement is associated. In afurther embodiment of the network management node 3304, one or moreinstant geographic locations estimated by the location module 3302 arealso based at least in part on a second signal strength measurement ofthe at least one signal strength measurement and a second RF coveragemap for a second sector antenna with which the second signal strengthmeasurement is associated, the second sector antenna associated with aneighboring base station in relation to the base station serving themobile station.

In still yet another embodiment of the network management node 3304,parameter measurements are obtained by the input module 3300 and theinstant geographic locations are estimated by the location module 3302in response to detection of a dropped call for the one or more mobilestations.

With reference to FIG. 34, an exemplary embodiment of a non-transitorycomputer-readable medium storing program instructions that, whenexecuted by a computer, cause a corresponding computer-controlled deviceto perform a process 3400 for mapping an operating parameter in acoverage area of a wireless network. In one embodiment, the process 3400begins at 3402 wherein parameter measurements for a select operatingparameter associated with one or more mobile stations operating in atleast a select portion of a network coverage area for a wireless networkare obtained. The parameter measurements having been measured during aselect calendar timeframe. The network coverage area formed by aplurality of base stations. Each base station defining a cellularcoverage area within the network coverage area. The select portion ofthe network coverage area formed by at least one base station. Each atleast one base station including multiple sector antennas. Each sectorantenna defining a sector coverage area within the cellular coveragearea for the corresponding base station. At 3404, for each obtainedparameter measurement, an instant geographic location of thecorresponding mobile station is estimated in relation to the at leastone base station serving the corresponding mobile station. Each instantgeographic location based at least in part on a round trip measurementand at least one signal strength measurement associated with thecorresponding mobile station. Each round trip measurement associatedwith the at least one base station serving the corresponding mobilestation. Each round trip measurement and corresponding at least onesignal strength measurement related in calendar time to thecorresponding parameter measurement.

In another embodiment, the process 3400 may also include processing theobtained parameter measurements for each instant geographic location toobtain a representative parameter value for the corresponding instantgeographic location. In this embodiment, a coverage area map for thewireless network is populated with the representative parameter valuesbased at least in part on the instant geographic location associatedwith the corresponding representative parameter value. In the embodimentbeing described, the coverage area map includes at least the selectportion of the network coverage area.

In various embodiments, the program instructions stored in thenon-transitory computer-readable memory, when executed by the computer,may cause the computer-controlled device to perform various combinationsof functions associated with the various embodiments of the processes2800, 2900, 3000, 3100, and 3200 for mapping an operating parameter in acoverage area of a wireless network described above with reference toFIGS. 28-32. In other words, the various embodiments of the processes2800, 2900, 3000, 3100, and 3200 described above may also be implementedby corresponding embodiments of the process 3400 associated with theprogram instructions stored in the non-transitory computer-readablememory.

Similarly, the program instructions stored in the non-transitorycomputer-readable memory, when executed by the computer, may cause thecomputer-controlled device to perform various combinations of functionsassociated with the various embodiments of the processes for estimatinga geographic location of a mobile station 400, 500, 1700, 1800, 1900,2000, 2100, 2200, and 2300 (see FIGS. 4, 5, and 17-23) in conjunctionwith estimating the instant geographic location of a mobile station in3404. In other words, the various embodiments of the processes 400, 500,1700, 1800, 1900, 2000, 2100, 2200, and 2300 described above may also beimplemented by corresponding embodiments of the process 3400 associatedwith the program instructions stored in the non-transitorycomputer-readable memory, particularly the estimating of the instantgeographic location in 3404.

Likewise, in various embodiments, the program instructions stored in thenon-transitory computer-readable memory, when executed by the computer,may cause the computer-controlled device to perform various combinationsof functions associated with the various embodiments of the apparatusfor mapping an operating parameter in a coverage area of a wirelessnetwork described above with reference to FIG. 33, the apparatus forestimating a geographic location of a mobile station described abovewith reference to FIG. 8, and the angular position module 906 describedabove with reference to FIG. 9.

For example, the computer-controlled device may include a networkmanagement node (see FIG. 33, item 3304; FIG. 8, item 828), or anysuitable communication node associated with the wireless network. Anysuitable module or sub-module described above with reference to FIGS. 8,9, and 33 may include the computer and non-transitory computer-readablememory associated with the program instructions. Alternatively, thecomputer and non-transitory computer-readable memory associated with theprogram instructions may be individual or combined components that arein operative communication with any suitable combination of the modulesand sub-modules described above with reference to FIGS. 8, 9, and 33.

With reference to FIG. 13, a functional diagram shows three basestations, each with three sector antennas, in relation to exemplaryembodiments of various techniques for estimating the geographic locationof a mobile station by dividing the wireless service area into differentcategories of circumstances for estimating the location. Different typesof data are available for the different categories. Thus, the techniquesfor estimating geographic location are adjusted for each category basedon the type of data available under the corresponding circumstance.

In a category 1 area, mobile station locations can be determined by analgorithm that calculates an angular position of the mobile station inrelation to a serving or neighboring base station using signal strengthmeasurements from multiple sector antennas of the base station in ameasurement report from the mobile station and determines a radialdistance of the mobile station from the serving base station based on around trip measurement. Various embodiments of algorithms for thecategory 1 area are provided below in the descriptions of FIGS. 1-12 and17-19.

With continued reference to FIG. 13, category 2 areas are locations inwhich the mobile station is only receiving signal strength measurementsfrom one sector antenna from each of one, two, or more base stations.Category 2 areas can be viewed as the rest of the coverage area for agiven cell (or given sector) of the wireless network that do not fitunder the category 1 circumstances. In a category 2 area, the mobilestation location is determined based on the combination of determining aradial distance of the mobile station from a serving based station basedon a round trip measurement and a strength measurements from one sectorantenna of each of one, two, or more base stations in a measurementreport from the mobile station to identify potential sub-sectorgeographic coverage areas in an RF coverage map for a serving sectorantenna of the serving base station populated with an RF coverage levelrepresentative of lacking previous signal strength measurements, andusing RF coverage levels in the RF coverage map for neighboringsub-sector geographic coverage areas to estimate the geographic locationof the mobile station. Various embodiments of algorithms for thecategory 1 area are provided below in the descriptions of FIGS. 6-10 and20-22.

With continued reference to FIG. 13, for each sub-sector geographic areain the RF coverage map, a geo-bin is used to store signal strengths forthe corresponding sub-sector geographic area. The RF coverage level forthe sub-sector geographic area is updated over time by averaging (or bytaking a median value) over multiple records of signal strengthmeasurements. Study has shown that the longer the observation period,the more accurate the results are for the corresponding RF coveragelevel. For example, eight hours of signal strength measurements resultsin an RF coverage level that is more accurate than signal strengthmeasurements spanning one hour for the same area.

An exemplary embodiment of techniques for estimating the geographiclocation of a mobile station for category 1 and category 2 circumstancesare described below. RF coverage maps may be built up by taking enoughmeasurement data over a suitable period of time to generate suitableinitial RF coverage maps. For example, taking eight hours of per callmeasurement data (PCMD) in down town busy areas may be used to generatean RF coverage map. The RF coverage maps my be built up from geographiclocations for the mobile stations obtained using the techniquesdescribed herein or by other suitable location determining techniques.

The measurement data may be divided into category 1 and category 2circumstances. Category 1 measurements contain signal strengthmeasurements by the mobile station from the same base station, butdifferent sectors. The rest of the measurement data belongs to category2 circumstances.

Each category may be further divided into sub categories. An example ofhow to generate an initial RF coverage map for base station 1, sector αfor subcategory 1A circumstances is based on the mobile station seeingtwo pilots from different sectors (sector α and sector β) of basestation 1. Both pilots may be used to estimate the mobile stationlocation by using a suitable embodiment of the algorithm disclosedherein. In addition, the pilot from base station 1, sector α may also beused to plot an RF coverage map for the corresponding sector α antennabased on category 1A geographic location estimates for the mobilestation.

Similarly, an example of how to generate an initial RF coverage map forbase station 1, sector α for subcategory 1B circumstances is based onthe mobile station seeing two pilots from different sectors (sector βand sector γ) of base station 3 and one pilot from base station 1,sector α. The two pilots from base station 3, sector β and sector γ areused to estimate the mobile location by using the algorithm disclosedherein. The pilot from base station 1, sector α may be used to plot anRF coverage map for the corresponding sector α antenna based on category1B geographic location estimates for the mobile station.

As for subcategory 2A, the mobile station only sees a single pilot frombase station 1, sector α. Hence, in subcategory 2A circumstances, themobile station is around a bore sight area for base station 1, sector αwhere it is most likely that only one pilot is seen by the mobilestation. Here, the mobile station location is estimated by using thepilot information, distance information, and RF coverage levels andcorresponding geo-bin information for sub-sector geographic areas thatare neighboring potential sub-sector geographic areas with RF coveragelevels showing that previous signal strength measurements are lacking.With the geographic location for the mobile station identified, thepilot from base station 1, sector α may also be used to supplement (orplot) an RF coverage map of the sector under category 2 circumstances.

As for subcategory 2B, the mobile station sees one pilot from basestation 1, sector α and another pilot from base station 2, sector β.Hence, in subcategory 2B circumstances, the mobile station is around anarea between base station 1 and base station 2. Here, the mobile stationlocation is estimated using both pilots information and distanceinformation combined with RF coverage levels and corresponding geo-bininformation for sub-sector geographic areas that are neighboringpotential sub-sector geographic areas with RF coverage levels showingthat previous signal strength measurements are lacking to get a moreaccurate estimation of the mobile station location. With the geographiclocation for the mobile station identified, the pilot from base station1, sector α may also used to supplement (or plot) an RF coverage map ofthe sector under category 2 circumstances.

With reference to FIG. 14, an example of an RF coverage map for a sectorantenna of a base station is shown that can be used in conjunction withan exemplary embodiment of a technique for estimating the geographiclocation of a mobile station. In various exemplary embodiments oftechniques for estimating the geographic location of a mobile station,the category 1 measurements can be used to build category 1 RF coveragemaps (including measurements associated with subcategory 1A andsubcategory 1B circumstances). Various embodiments of the algorithm toobtain mobile station geographic location in category 1 circumstances isdescribed in more detail below in the descriptions of FIGS. 1-12 and17-19.

With continued reference to FIGS. 14 and 15, signal strengthmeasurements from category 2 circumstances can be combined with category1 RF coverage maps and/or existing signal strength measurementinformation stored in geo-bins associated with neighboring sub-sectorgeographic areas to generate category 2 RF coverage maps. For example,in FIG. 14, in a category 1 area, including areas for subcategory 1A andsubcategory 1B circumstances, an RF coverage map for base station A,sector 3 is already built from previous category 1 signal strengthmeasurements. The category 1 RF coverage map shows that areas forsubcategory 2A and subcategory 2B for base station A, sector 3 do notcurrently have valid Ec/lo information.

As for subcategory 2A, the mobile station sees a pilot from base stationA, sector 3 with Ec/lo at −5 dB. In the mean time, base station A,sector 3 measured the round trip delay associated with the mobilestation to be equivalent to distance d. In this example, there are twosub-sector geographic areas and corresponding geo-bins that areassociated with the distance d criteria in the area associated withsubcategory 2A circumstances. The technique goes on to determine whichsub-sector geographic area or corresponding geo-bin signal measurementsin the area for subcategory 2A circumstances is associated with themobile station location.

In the embodiment being described, the sub-sector geographic area andcorresponding geo-bin in the base station A, sector 3 area just north ofthe area associated with subcategory 2A circumstances has Ec/lo at −2dB. The sub-sector geographic area and corresponding geo-bin in the basestation A, sector 3 area just south of the area associated withsubcategory 2A circumstances has Ec/lo at −6 dB. In this embodiment, thesouthern sub-sector geographic area and corresponding geo-bin in areaassociated with subcategory 2A circumstances is chosen to indicate themobile station location because the measurement report of pilot Ec/lo at−5 dB is closer to −6 dB than −2 dB. The updated overall RF coverage mapfor base station A, sector 3 is shown in FIG. 15.

With continued reference to FIG. 14, as for subcategory 2B, the mobilestation sees a pilot from base station A, sector 3 with Ec/lo at −7 dBand another pilot from base station B, sector 2. In the mean time, basestation A, sector 3 measured the round trip delay associated with themobile station to be equivalent to distance d. In this example, thereare two sub-sector geographic areas and corresponding geo-bins that areassociated with the distance d in the area associated with subcategory2B measurements. In the embodiment being described, the sub-sectorgeographic areas and corresponding geo-bins neighboring the areasassociated with the category 2B circumstances in the base station A,sector 3 coverage area have pilot Ec/lo signals around −7 dB. The nextstep is to determine which sub-sector geographic area and correspondinggeo-bin in the potential category 2B areas the mobile station islocated.

In the embodiment being described, the northern sub-sector geographicarea and corresponding geo-bin is chosen to indicate the mobile stationlocation because the northern bin is located between base station A andbase station B where it is most likely that pilots from both basestations can be seen by the mobile station. The updated overall RFcoverage map for base station A, sector 3 is shown in FIG. 15.

With reference to FIGS. 14 and 15, the RF coverage level for thesub-sector geographic area can continue to be updated in the RF coveragemaps for each individual base station (i.e., sector antenna) byaveraging (or by taking the median value) over multiple records for acorresponding geo-bin.

With reference to FIG. 16, yet another example of an RF coverage map fora sector antenna of a base station is shown that can be used inconjunction with another exemplary embodiment of a technique forestimating the geographic location of a mobile station. In thisembodiment, the geographic location of a mobile station can be estimatedbased on RF coverage maps for various circumstances, such as droppedcall locations. Study has shown that the longer the observation period,the more accurate the results are for the corresponding RF coveragelevel. On the other hand, for some events, like dropped calls, it isvery important to know where the calls are dropped. However, undernormal circumstances, dropped calls are not experienced very often inthe wireless network. In another exemplary embodiment, a technique forestimating the location of a mobile station includes an algorithm toestimate dropped call locations for mobile stations on existing RFcoverage maps.

In this embodiment, the mobile station reports Ec/lo of base station A,sector 3 at −3 dB and Ec/lo of base station B, sector 3 at −4 dB. Thedistance between the mobile station and the serving sector antenna(i.e., base station A, sector 3) is determined to be distance d. Theprocess uses existing RF coverage maps for these sectors to identify RFcoverage levels and corresponding geo-bins that closely match thesesignal strength measurements. Moreover, the process uses the distancemeasurement to define a circle centered at base station A with a radiusdefined by distance d on which the closely matching RF coverage levelsand corresponding geo-bins are identified.

For example, the closely matching RF coverage levels for sub-sectorgeographic areas and corresponding geo-bins in a first RF coverage mapfor base station A may have Ec/lo values within a range of −3dB+/−Threshold_s, where Threshold_s is a threshold for the servingsector antenna (i.e., base station A, sector 3). For example,Threshold_s can be set at 0.25 dB. Similarly, the closely matching RFcoverage levels for sub-sector geographic areas and correspondinggeo-bins in a second RF coverage map for base station B may have Ec/lovalues within a range of −4 dB+/−Threshold_n, where Threshold_n is athreshold for the neighboring sector antenna (i.e., base station B,sector 3). For example, Threshold_n can be set at 0.5 dB. The red dot inFIG. 16 shows the estimated mobile station location after overlaying thesub-sector geographic area identified in the second RF coverage map onthe first RF coverage map to locate matching RF coverage levels fromboth RF coverage maps that intersect.

With reference to FIG. 17, an exemplary embodiment of a process 1700 forestimating a geographic location of a mobile station within a coveragearea of a wireless network begins at 1702 where an instant angularposition of an individual mobile station in relation to a first basestation is calculated. The first base station including multiple sectorantennas. The instant angular position based at least in part on a firstsignal strength measurement, a second signal strength measurement, andan angular position reference that extends outward from the first basestation. The first and second signal strength measurements related incalendar time and representative of power characteristics of respectiveRF signals received by the individual mobile station from correspondingfirst and second sector antennas of the first base station.

With reference to FIGS. 17 and 18, another exemplary embodiment of aprocess 1800 for estimating a geographic location of a mobile stationwithin a coverage area of a wireless network includes the process 1700of FIG. 17 and continues at 1802 where a radial distance of theindividual mobile station from the first base station is determined. Theradial distance based at least in part on a round trip measurementassociated with elapsed time between sending an outgoing signal from thefirst base station to the individual mobile station and receiving acorresponding acknowledgement signal from the individual mobile stationat the first base station. The round trip measurement related incalendar time to the first and second signal strength measurements.

In another embodiment, the process 1800 also includes identifying aninstant geographic location of the individual mobile station in acoverage area of a wireless network formed by at least the first basestation. The instant geographic location based at least in part on anintersection of a line extending outward from the first base station atthe instant angular position with a circle having a center defined bythe first base station and a radius defined by the radial distance.

In further embodiment, the process 1800 also includes correlating theinstant geographic location of the individual mobile station with afirst sub-sector geographic area in a first RF coverage map for thefirst sector antenna based at least in part on a reference location forthe first base station in the first RF coverage map. The first RFcoverage map formed by a plurality of sub-sector geographic areas. Eachsub-sector geographic area uniquely identified and associated with acorresponding geographic location bin for the first RF coverage map forstorage of signal strength measurements from the first sector antennaassociated with the corresponding sub-sector geographic area. In thisembodiment, the process 1800 also includes sending the first signalstrength measurement to a first geographic location bin associated withthe unique identifier for the first sub-sector geographic area forstorage in conjunction with computation of a representative RF coveragelevel for populating the first sub-sector geographic area in the firstRF coverage map.

In another further embodiment, the process 1800 also includescorrelating the instant geographic location of the individual mobilestation with a second sub-sector geographic area in a second RF coveragemap for the second sector antenna based at least in part on a referencelocation for the first base station in the second RF coverage map. Thesecond RF coverage map formed by a plurality of sub-sector geographicareas. Each sub-sector geographic area uniquely identified andassociated with a corresponding geographic location bin for the secondRF coverage map for storage of signal strength measurements from thesecond sector antenna associated with the corresponding sub-sectorgeographic area. In this embodiment, the process 1800 also includessending the second signal strength measurement to a second geographiclocation bin associated with the unique identifier for the secondsub-sector geographic area for storage in conjunction with computationof a representative RF coverage level for populating the secondsub-sector geographic area in the second RF coverage map.

With reference to FIGS. 17 and 19, yet another exemplary embodiment of aprocess 1900 for estimating a geographic location of a mobile stationwithin a coverage area of a wireless network includes the process 1700of FIG. 17 and continues at 1902 where a radial distance of theindividual mobile station from a second base station serving theindividual mobile station is determined. The second base stationincluding multiple sector antennas. The radial distance based at leastin part on a round trip measurement associated with elapsed time betweensending an outgoing signal from the second base station to theindividual mobile station and receiving a corresponding acknowledgementsignal from the individual mobile station at the second base station.The round trip measurement related in calendar time to the first andsecond signal strength measurements.

In another embodiment, the process 1900 also includes identifying aninstant geographic location of the individual mobile station in acoverage area of a wireless network formed by at least the first andsecond base stations. The instant geographic location based at least inpart on an intersection of a line extending outward from the first basestation at the instant angular position with a circle having a centerdefined by the second base station and a radius defined by the radialdistance.

In a further embodiment of the process 1900, a signal strengthmeasurement report from the individual mobile station comprising thefirst and second signal strength measurements also includes a thirdsignal strength measurement. The third signal strength measurementrepresentative of the power characteristic of a third RF signal receivedby the individual mobile station from a third sector antenna of thesecond base station. In this embodiment, the process 1900 also includescorrelating the instant geographic location of the individual mobilestation with a third sub-sector geographic area in a third RF coveragemap for the third sector antenna based at least in part on a referencelocation for the second base station in the third RF coverage map. Thethird RF coverage map formed by a plurality of sub-sector geographicareas. Each sub-sector geographic area uniquely identified andassociated with a corresponding geographic location bin for the third RFcoverage map for storage of signal strength measurements from the thirdsector antenna associated with the corresponding sub-sector geographicarea. In the embodiment being described, the process 1900 also includessending the third signal strength measurement to a third geographiclocation bin associated with the unique identifier for the thirdsub-sector geographic area for storage in conjunction with computationof a representative RF coverage level for populating the thirdsub-sector geographic area in the third RF coverage map.

With reference to FIG. 20, still another exemplary embodiment of aprocess 2000 for estimating a geographic location of a mobile stationwithin a coverage area of a wireless network begins at 2002 where aradial distance of an individual mobile station from a first basestation serving the individual mobile station is calculated. The firstbase station including multiple sector antennas. The radial distancebased at least in part on a round trip measurement associated withelapsed time between sending an outgoing signal from the first basestation to the individual mobile station and receiving a correspondingacknowledgement signal from the individual mobile station at the firstbase station. Next, the process determines a signal strength report fromthe individual mobile station provided to the first base station relatedin calendar time to the round trip measurement includes a first signalstrength measurement representative of a power characteristic of a firstRF signal received by the individual mobile station from a first sectorantenna of the first base station (2004). The signal strength report notincluding other signal strength measurements for other sector antennasof the first base station.

At 2006, an instant geographic location of the individual mobile stationis identified in a coverage area of a wireless network formed by atleast the first base station. The instant geographic location based atleast in part on an intersection of a circle having a center defined bythe first base station and a radius defined by the radial distance witha first sub-sector geographic area in a first RF coverage map for thefirst sector antenna. The first RF coverage map including a firstreference location for the first base station to facilitate correlationof the circle to the first RF coverage map. The first RF coverage mapformed by a plurality of sub-sector geographic areas. The first RFcoverage map populated with representative RF coverage levels associatedwith previous signal strength measurements for the first sector antennafrom one or more mobile stations in previous signal strength reportscomprising the corresponding previous signal strength measurement and atleast one signal strength measurement from another sector antenna of thefirst base station. The first sub-sector geographic area in the first RFcoverage map is populated with a first RF coverage level representativeof lacking previous signal strength measurements.

With reference to FIGS. 20 and 21, still yet another exemplaryembodiment of a process 2100 for estimating a geographic location of amobile station within a coverage area of a wireless network includes theprocess 2000 of FIG. 20. In this embodiment of the process 2100, eachsub-sector geographic area is uniquely identified and associated with acorresponding geographic location bin for the first RF coverage map forstorage of previous signal strength measurements from the first sectorantenna associated with the corresponding sub-sector geographic area anda first geographic location bin associated with the first RF coveragemap and the first sub-sector geographic area is void of previous signalstrength measurements (2102).

In another embodiment, the process 2100 also includes identifyingmultiple sub-sector geographic areas in the first RF coverage mapintersecting the circle associated with the first base station that arepopulated with the first RF coverage level. In this embodiment, thefirst signal strength measurement is compared to representative RFcoverage levels associated with previous signal strength measurementsstored in corresponding geographic location bins for correspondingsub-sector geographic areas of the first RF coverage map neighboringeach of the multiple sub-sector geographic areas. In the embodimentbeing described, the first sub-sector geographic area is selected fromthe multiple sub-sector geographic areas based at least in part on theneighboring RF coverage level for the first sub-sector geographic areabeing associated with previous signal strength measurements that arecloser to the first signal strength measurement than previous signalstrength measurements associated with neighboring RF coverage levels forother sub-sector geographic areas of the multiple sub-sector geographicareas.

In yet another embodiment, the process 2100 also includes sending thefirst signal strength measurement to a first geographic location binassociated with the unique identifier for the first sub-sectorgeographic area for storage in conjunction with computation of arepresentative RF coverage level for populating the first sub-sectorgeographic area in a second RF coverage map for the first sectorantenna. The second RF coverage map formed by a plurality of sub-sectorgeographic areas. The second RF coverage map populated withrepresentative RF coverage levels associated with previous signalstrength measurements for the first sector antenna from one or moremobile stations in previous signal strength reports.

With reference to FIGS. 20 and 22, another exemplary embodiment of aprocess 2200 for estimating a geographic location of a mobile stationwithin a coverage area of a wireless network includes the process 2000of FIG. 20 and continues at 2202 with determining the signal strengthreport from the individual mobile station provided to the first basestation includes a second signal strength measurement representative ofthe power characteristic of a second RF signal received by theindividual mobile station from a second sector antenna of a second basestation. The second base station including multiple sector antennas. Inthis embodiment of the process 2200, the first RF coverage map includesa second reference location for the second base station.

In another embodiment, the process 2200 also includes identifyingmultiple sub-sector geographic areas in the first RF coverage mapintersecting the circle associated with the first base station that arepopulated with the first RF coverage level. In this embodiment,geographic locations of the multiple sub-sector geographic areas in thefirst RF coverage map are compared to a fixed location for the secondbase station in relation to the first RF coverage map. In the embodimentbeing described, the first sub-sector geographic area is selected fromthe multiple sub-sector geographic areas based at least in part on thegeographic location for the first sub-sector geographic area beingcloser to the fixed location for the second base station than thegeographic locations for other sub-sector geographic areas of themultiple sub-sector geographic areas.

In yet another embodiment, the process 2200 also includes correlatingthe instant geographic location of the individual mobile station with asecond sub-sector geographic area in a second RF coverage map for thesecond sector antenna based at least in part on a second referencelocation for the first base station in the second RF coverage map. Thesecond RF coverage map formed by a plurality of sub-sector geographicareas. Each sub-sector geographic area uniquely identified andassociated with a corresponding geographic location bin for the secondRF coverage map for storage of signal strength measurements from thesecond sector antenna associated with the corresponding sub-sectorgeographic area. In this embodiment, the process 2200 also includessending the second signal strength measurement to a second geographiclocation bin associated with the unique identifier for the secondsub-sector geographic area for storage in conjunction with computationof a representative RF coverage level for populating the secondsub-sector geographic area in the second RF coverage map for the secondsector antenna.

With reference to FIG. 23, yet another exemplary embodiment of a process2300 for estimating a geographic location of a mobile station within acoverage area of a wireless network begins at 2302 where a radialdistance of an individual mobile station from a first base stationserving the individual mobile station is calculated in response todetection of a dropped call for the mobile station. The first basestation including multiple sector antennas. The radial distance based atleast in part on a round trip measurement preceding detection of thedropped call and in proximate time relation to detection of the droppedcall. The round trip measurement associated with elapsed time betweensending an outgoing signal from the first base station to the individualmobile station and receiving a corresponding acknowledgement signal fromthe individual mobile station at the first base station. Next, theprocess determines a signal strength report from the individual mobilestation provided to the first base station preceding detection of thedropped call, in proximate time relation to detection of the droppedcall, and related in calendar time to the round trip measurementincludes a first signal strength measurement representative of a powercharacteristic of a first RF signal received by the individual mobilestation from a first sector antenna of the first base station (2304).

At 2306, an instant geographic location of the individual mobile stationis identified in a coverage area of a wireless network formed by atleast the first base station. Identification of the instant geographiclocation is based at least in part on an intersection of a circle havinga center defined by the first base station and a radius defined by theradial distance with a first sub-sector geographic area in a first RFcoverage map for the first sector antenna. The first RF coverage mapincluding a first reference location for the first base station tofacilitate correlation of the circle to the first RF coverage map. Thefirst RF coverage map formed by a plurality of sub-sector geographicareas. The first RF coverage map populated with representative RFcoverage levels associated with previous signal strength measurementsfor the first sector antenna from one or more mobile stations inprevious signal strength reports. The first sub-sector geographic areain the first RF coverage map is populated with an RF coverage levelrepresentative of a first signal strength value within a firstpredetermined threshold of the first signal strength measurement.

In another embodiment, the process 2300 also includes identifyingmultiple sub-sector geographic areas in the first RF coverage mapintersecting the circle associated with the first base station that arepopulated with RF coverage levels representative of first signalstrength values within the predetermined threshold of the first signalstrength measurement. In this embodiment, the process determines thesignal strength report from the individual mobile station provided tothe first base station includes a second signal strength measurementrepresentative of the power characteristic of a second RF signalreceived by the individual mobile station from a second sector antennaof a second base station, The second base station including multiplesector antennas.

In a further embodiment, the process 2300 also includes comparinggeographic locations of the multiple sub-sector geographic areas in thefirst RF coverage map to a fixed location for the second base station inrelation to the first RF coverage map. In this embodiment, the firstsub-sector geographic area is selected from the multiple sub-sectorgeographic areas based at least in part on the geographic location forthe first sub-sector geographic area being closer to the fixed locationfor the second base station than the geographic locations for othersub-sector geographic areas of the multiple sub-sector geographic areas.

In another further embodiment, the process 2300 also includescorrelating the circle associated with the first base station with asecond RF coverage map for the second sector antenna based at least inpart on the second RF coverage map including the first referencelocation for the first base station and a second reference location forthe second base station. The second RF coverage map formed by aplurality of sub-sector geographic areas. The second RF coverage mappopulated with representative RF coverage levels associated withprevious signal strength measurements for the second sector antenna fromone or more mobile stations in previous signal strength reports. In thisembodiment, the process 2300 also includes identifying a secondsub-sector geographic area in the second RF coverage map based at leastin part on the circle associated with the first base stationintersecting at least one sub-sector geographic area in the second RFcoverage map populated with an RF coverage level representative of asecond signal strength value within a second predetermined threshold ofthe second signal strength measurement. In the embodiment beingdescribed, the second sub-sector geographic area in the second RFcoverage map is correlated with the first RF coverage map based at leastin part on the first and second RF coverage maps including the first andsecond reference locations for the first and second base stations toidentify the first sub-sector geographic area.

In yet another further embodiment, the process 2300 also includesidentifying multiple prospective geographic locations for the mobilestation in a second RF coverage map for the second sector antenna. Thesecond RF coverage map including the first reference location for thefirst base station and a second reference location for the second basestation. The second RF coverage map formed by a plurality of sub-sectorgeographic areas. The second RF coverage map populated withrepresentative RF coverage levels associated with previous signalstrength measurements for the second sector antenna from one or moremobile stations in previous signal strength reports. The multipleprospective geographic locations based at least in part on thecorresponding sub-sector geographic areas in the second RF coverage mapbeing populated with an RF coverage level representative of a secondsignal strength value within a second predetermined threshold of thesecond signal strength measurement. In this embodiment, the process 2300also includes correlating the multiple prospective geographic locationsfor the mobile station in the second RF coverage map with the first RFcoverage map for the first sector antenna based at least in part on thefirst and second RF coverage maps including the first reference locationfor the first base station. In the embodiment being described,identification of the instant geographic location is based at least inpart on at least one of the multiple prospective geographic locationsintersecting the circle associated with the first base station in thefirst RF coverage map.

With reference to FIG. 2, in one embodiment, the technique forestimating the geographic location of the mobile station uses a roundtrip measurement (e.g., RTD measurement) from a serving base station(i.e., serving cell) to estimate the distance (d) of the mobile stationfrom the serving base station. Then, signal strength measurements fromserving and/or neighboring sectors of the serving base station toestimate an azimuth position (φ) of the mobile station in relation to anangular position reference extending outward from the serving basestation. Combining the sector coverage areas of the same base stationforms a corresponding cellular coverage area for the base station. Theindividual sector coverage areas may also be referred to as cells inrelation to corresponding sector antennas. If so, the correspondingcells for sector antennas associated with the same base station arestill usually labeled as sectors (e.g., α, β, γ sectors or sectors 1, 2,3). Normally, the sector antennas associated with the same base stationare mounted on the same cell tower (or building). Hence, the radio wavetravel from these sector antennas to a given mobile station antenna willexperience highly correlated losses (including path loss and shadowfading). The algorithm described herein uses these RF characteristics(i.e., highly correlated losses) to estimate an azimuth position of themobile station in relation to the serving based station based on thedifference of signal strength measurements from multiple sector antennasof the serving base station.

In one embodiment, the algorithm for estimating a geographic location ofa mobile station within a coverage area of a wireless network beginswith estimating a distance (d) of the mobile station from the servingbase station based on a round trip measurement, such as RTD. Next, theazimuth position (φ) of the mobile station in relation to the servingbase station is estimated based on signal strength measurements by themobile station from multiple sector antennas of the serving base stationthat are reported back by the mobile station to the serving base stationvia the serving sector antenna. Combining the distance (d) and azimuthposition (φ) forms a geographic location of the mobile station inrelation to the serving base station with respect to vector representedby a displacement (i.e., distance (d)) and an angular position (i.e.,azimuth position (φ)). This polar coordinate-type of geographic notationcan be converted to various other forms of geographic notation,including a latitude/longitude notation, an address notation, or ageo-bin tile grid notation associated with the coverage area for thewireless network. For example, the geo-bin tile grid notation may use 50meter by 50 meter tiles to represent the coverage area for a sectorantenna, base station, cluster of base stations, or the overall wirelessnetwork. In other embodiments, any suitable tile size may be used toprovide a higher or lower resolution of the coverage area.

The approximation algorithm for estimating the geographic location of amobile station may be based on certain considerations regarding themobile received power (Pr) (i.e., signal strength measurements) frommultiple sector antennas where the sector antennas are located in closeproximity to each other, such as mounted on the same cell tower or onthe same physical structure at relatively the same elevation. Forexample, the mobile received power (Pr) is received by the mobilestation from multiple sector antennas of the serving base station. Themobile station measures the signal strength of the mobile received power(Pr) signals and may report back the corresponding signal strengthmeasurements in dBm.

Mobile received power (Pr) may be represented by the following equation:Pr(d,φ,θ)=Pt−PL(d)−X+Gt(d,φ,θ)+Gr  (1),where d is a distance between the serving base station and the mobilestation in kilometers (km), φ is an azimuth position of the mobilestation in relation to an angular position reference extending outwardfrom the serving base station, θ is an azimuth position at which thetransmit portion of the corresponding sector antenna is oriented inrelation to the angular reference position, Pt is a transmit power forthe corresponding sector antenna in dBm, and PL(d) is an average pathloss in dB for the corresponding sector antenna. The azimuth position θof the sector antenna is known and corresponds to its actualinstallation. Likewise, the transmit power Pt for the sector antenna isknown at the serving base station based on known characteristics of thesector antenna or actual measurements by the base station.

The average path loss PL(d) may be represented by the followingequation:PL(d)=K1+K2*log 10(d)  (2),where K1 and K2 are propagation parameters such that K1 is function ofmorphology, frequency, cell antenna height, and mobile antenna heightand K2 is function of cell antenna height.

With reference again to equation (1), X is a zero-mean Gaussiandistributed random variable (in dB) with standard deviation aapproximately equal to N(0, σ). (in dB). X may be referred to as theshadowing fading effect. Gt(d, φ, θ) is the transmit antenna gain at thesector antenna in dB. Gr is receive antenna gain at the mobile stationin dB.

With reference to FIG. 3, Gt(d, φ, θ) reflects that Gt is a function ofmobile distance (d) and an angle between the azimuth position (φ) of themobile station and the azimuth position (θ) of the corresponding sectorantenna. Note, the distance (d), in combination with the sector antennaheight, is used to estimate an antenna tile and an antenna downtile. Theazimuth position (φ) of the mobile station and the azimuth position (θ)of the corresponding sector antenna are used to determine a horizontalgain portion of Gt, where the look angle is φ−θ. The distance (d) andthe height (i.e., elevation) of the corresponding sector antenna areused to determine a vertical gain component of Gt.

The signal strength measurements for mobile received power Pr may bereported as received signal reference power (RSRP) measurements,reference signal received quality (RSRQ) measurements, or Ec/lomeasurements. RSRQ is the ratio of received signal reference power tototal received power. Ec/lo is the ratio in dB between the pilot energyaccumulated over one PN chip period (“Ec”) to the total power spectraldensity in the received bandwidth (“lo”).

Mobile received power Pr1 and Pr2 from two sector antennas of theserving base station in dBm may be represented by the followingequations:Pr1(d,φ,θ1)=Pt1−PL(d)−X+Gt1(d,φ,θ1)+Gr  (3),Pr2(d,φ,θ2)=Pt2−PL(d)−X+Gt2(d,φ,θ2)+Gr+ε  (4).

The path loss and shadowing fading effect from different sector antennasof the same base station can be assumed to be equal where the sectorantennas are mounted on the same cell tower or building. The closeproximity of the sector antennas results in high correlation of betweenthese components of the mobile received power Pr1 and Pr2. For example,the differences of shadow fading are expected to be very small and arecounted by E in equation (4). As mentioned above, d, θ1 and θ2 are knownvalues.

Based on the foregoing, an estimate of the azimuth position (φ) of themobile station may be based on the difference of mobile received powerfrom the two sector antennas (Pr1−Pr2) in dB. For example, (Pr1−Pr2) canbe (RSRP1−RSRP2) or (RSRQ1−RSRQ2) in an LTE network. Similarly,(Pr1−Pr2) can be (Ec/lo)1−(Ec/lo)2 in a CDMA network. Even though themobile received power Pr1 and Pr2 are expressed in absolute receivedpower format (i.e., dBm), the estimation of mobile location does notrequire the knowledge of absolute received power information. RSRQ forLTE and pilot Ec/lo for CDMA can be used in the same manner as mentionedabove.

Based on the foregoing, the difference between the mobile received powerPr1 and Pr2 can be represented by the following equation:(Pr1−Pr2)=(Gt1(φ)−Gt2(φ))+(Pt1−Pt2)  (5),where φ can be substituted with a potential azimuth position φm for themobile station in the range of 0 to 360 degrees. The potential azimuthposition φm that results in the closest match between the right and leftsides of equation (5) can be used as estimated azimuth position of themobile station.

Based on the foregoing, the azimuth position of the mobile station canbe represented by the following equation:F(φ)=|(Gt1(φ)−Gt2(φ))+(Pt1−Pt2)−(Pr1−Pr2)|  (6),where φ can be substituted with a potential azimuth position φm for themobile station in the range of 0 to 360 degrees. The potential azimuthposition φm that minimizes F(φm) can be used as estimated azimuthposition of the mobile station.

This process can also be expressed in the following equation:min|(Gt1(φ)−Gt2(φ))+(Pt1−Pt2)−(Pr1−Pr2)|  (7).

Notably, the value selected for the initial potential azimuth positionφm in equations (5) through (7) can be based at least in part on theknowledge of the orientation and azimuth position of the serving sectorantenna. Subsequent values selected for the potential azimuth positionφm can be based on whether the subsequent result is approaching orreceding from the desired result. Various techniques can also be used toselect subsequent values for the potential azimuth position φm based onthe magnitude of the difference between the subsequent result and thedesired result as well as the change in the difference betweenconsecutive subsequent results and the desired result.

With reference to FIG. 11, a bird's eye view of a coverage area of anexemplary base station A in a wireless network shows an estimatedgeographic location for a mobile station (UE) resulting from the processdisclosed herein. A geographic location for the mobile station (UE)based on GPS location is also shown for comparison. The X and Y axes forthe coverage area reflect distance in meters from the base station A.Notably, the estimated geographic location is close to the GPS location.

The base station A includes a first sector antenna oriented at 27degrees from north (i.e., an angular position reference representing0/360 degrees) and a second sector antenna oriented at 267 degrees. Themobile station reported signal strength measurements from the first andsecond sector antennas at −11 dB and −13 dB, respectively. The angularposition of the mobile station was estimated at 330.6 degrees using theprocess disclosed herein. The measurements used to estimate thegeographic location of the mobile station were retrieved from per callmeasurement data (PCMD) for an active call associated with the mobilestation. For example, the PCMD data may be stored by a wireless serviceprovider during network operations for billing purposes. The processdisclosed herein may use signal strength measurements and round tripmeasurements captured and retained during network operations via anysuitable techniques without requiring additional network overhead forcollection of data to perform the estimate of the geographic location ofthe mobile station.

With reference to FIG. 12, various data and calculations associated withthe process for estimating the geographic location of a mobile stationis provided in a set of graphs. The upper left graph shows an azimuthgain parameter characteristic for a first sector antenna of a servingbase station. The first sector antenna is oriented at 27 degrees fromnorth (i.e., an angular position reference representing 0/360 degrees).The middle left graph shows an azimuth gain parameter characteristic fora second sector antenna of a serving base station. The second sectorantenna is oriented at 267 degrees from north. The azimuth gainparameter characteristics may be manufacturer's specifications of powermeasurements from the sector antennas from relatively close (e.g., 10meters) to the base station where little or no path loss is experienced.As shown, the first and second sector antennas have the same azimuthgain characteristic merely shifted by the orientation of the antennas.In other base station arrangements, the sector antennas may havedifferent azimuth gain characteristics.

The upper right graph shows an elevation gain parameter characteristicfor the first sector antenna. The first sector antenna is oriented at 2degrees down from horizontal (i.e., an elevation position referencerepresenting 0/360 degrees). The middle right graph shows an elevationgain parameter characteristic for the second sector antenna. The secondsector antenna is also oriented at 2 degrees down from horizontal. Theelevation gain parameter characteristics may be manufacturer'sspecifications of power measurements from the sector antennas fromrelatively close (e.g., 10 meters) to the base station where little orno path loss is experienced. As shown, the first and second sectorantennas have the same elevation gain characteristic. In other basestation arrangements, the sector antennas may have different elevationgain characteristics. Also, the sector antennas may be oriented atdifferent angles from the horizontal in other base station arrangements.

The lower left graph is a composite graph showing the difference betweengains for the first and second sector antennas. The composite graphtakes the azimuth and elevation gain characteristics into account toform a composite delta gain characteristic. The composite graph reflectsdifferences in relation to varying azimuth position that follows theazimuth gain characteristics and a relatively steady state componentfrom the elevation gain characteristics because the elevation tilt ofthe antennas is not changing. The following equation is used to populatethe composite graph:(Gt1(φ)_(az) +Gt1_(el) −Gt1_(max))−(Gt2(φ)_(az) +Gt2_(el)−Gt2_(max))  (8),where Gt1(φ)_(az) is the azimuth gain for the first sector antenna for agiven azimuth angle in relation to the angular position reference, Gt1_(el) is the elevation gain for the first antenna associated with theelevation tilt, and Gt1 _(max) is the maximum gain for the first sectorantenna. Similarly, Gt2(φ)_(az) is the azimuth gain for the secondsector antenna for a given azimuth angle in relation to the angularposition reference, Gt2 _(el) is the elevation gain for the secondantenna associated with the elevation tilt, and Gt2 _(max) is themaximum gain for the second sector antenna.

The lower right graph shows a function of the angular position of themobile station in relation to the delta antenna gain component, a deltatransmit parameter component, and a delta signal strength measurementcomponent as defined above in equation (7).

With reference to FIG. 4, an exemplary embodiment of a process 400 forestimating a geographic location of a mobile station within a coveragearea of a wireless network begins at 402 where a radial distance of amobile station from a base station serving the mobile station isdetermined. The base station includes multiple sector antennas. Theradial distance is based at least in part on a round trip measurementassociated with elapsed time between sending an outgoing signal from thebase station to the mobile station and receiving a correspondingacknowledgement signal from the mobile station at the base station. At404, a current angular position of the mobile station in relation to theradial distance from the serving base station is calculated. The currentangular position is based at least in part on a first signal strengthmeasurement, a second signal strength measurement, and an angularposition reference that extends outward from the serving base station.The first and second signal strength measurements representative ofpower characteristics of respective RF signals received by the mobilestation from corresponding first and second sector antennas of theserving base station.

With reference to FIGS. 4 and 5, another exemplary embodiment of aprocess 500 for estimating a geographic location of a mobile stationwithin a coverage area of a wireless network includes the process 400 ofFIG. 4 and continues at 502 where a current geographic location of themobile station in a coverage area of the wireless network is identifiedin a geographic notation. The geographic notation is based at least inpart on combining the radial distance and current angular position ofthe mobile station relative to the serving base station. In oneembodiment, the radial distance and current angular position reflect apolar coordinate-type of geographic notation in reference to the servingbase station. In other embodiments, the radial distance and currentangular position can be converted into various types of geographicnotation, such as a latitude/longitude notation, an address notation, ora geo-bin tile grid notation associated with the coverage area for thewireless network.

In another embodiment, the process 500 also includes sending the currentgeographic location of the mobile station in the geographic notation toa geo-location storage node associated with the wireless network. In afurther embodiment, the determining, calculating, identifying, andsending are performed by the serving base station.

In yet another embodiment, the process 500 also includes receiving theround trip measurement, first signal strength measurement, and secondsignal strength measurement from the serving base station via thewireless network at a geo-location service node associated with thewireless network. In this embodiment, the current geographic location ofthe mobile station is sent in the geographic notation to a geo-locationstorage device associated with the geo-location service node. In theembodiment being described, the receiving, determining, calculating,identifying, and sending are performed by the geo-location service node.

In still another embodiment, the process 500 also includes receiving theround trip measurement, first signal strength measurement, and secondsignal strength measurement from the serving base station via thewireless network at a network management node associated with thewireless network. In this embodiment, the round trip measurement, firstsignal strength measurement, and second signal strength measurement arestored at a measurements storage device associated with the networkmanagement node. In the embodiment being described, the round tripmeasurement, first signal strength measurement, and second signalstrength measurement are retrieved from the measurements storage devicein conjunction with the determining and calculating. In this embodiment,the process 500 also includes sending the current geographic location ofthe mobile station in the geographic notation to a geo-location storagedevice associated with the network management node. The receiving,storing, retrieving, determining, calculating, identifying, and sendingare performed by the network management node in the embodiment beingdescribed.

With reference again to FIG. 4, in another embodiment of the process400, the round trip, first signal strength, and second signal strengthmeasurements are related in calendar time. In a further embodiment, theradial distance and current angular position of the mobile stationrelative to the serving base station are indicative of a currentgeographic location of the mobile station in a coverage area of thewireless network in relation to the calendar time associated with theround trip, first signal strength, and second signal strengthmeasurements.

In yet another embodiment of the process 400, the first sector antennais serving the mobile station and referred to as a serving sectorantenna and the second sector antenna is disposed near the first sectorantenna and referred to as a neighboring sector antenna. In stillanother embodiment of the process 400, the round trip measurement ismeasured by the serving base station. In a further embodiment, the roundtrip measurement includes a RTD time measurement. In still yet anotherembodiment of the process 400, the first and second signal strengthmeasurements are measured by the mobile station. In a furtherembodiment, the first and second signal strength measurements includeRSRP measurements, RSRQ measurements, or Ec/lo measurements.

In another embodiment of the process 400, the calculating in 404 mayinclude retrieving first and second transmit parameter values from astorage device associated with the wireless network. The first andsecond transmit parameter values representative of power characteristicsof respective communication signals to be transmitted by thecorresponding first and second sector antennas. In this embodiment, thecalculating in 404 may also include determining a difference between thefirst and second transmit parameter values to obtain a first angularposition component.

In a further embodiment of the process 400, the calculating in 404 mayalso include retrieving the first and second signal strengthmeasurements from the storage device. In this embodiment, thecalculating in 404 may also include determining a difference between thefirst and second signal strength measurements to obtain a second angularposition component.

In a yet further embodiment of the process 400, the calculating in 404may also include retrieving a first antenna elevation gain parametervalue, a first antenna maximum gain parameter value, and a first antennaazimuth gain parameter characteristic from the storage device. The firstantenna azimuth gain parameter characteristic relating first antennaazimuth gain parameter values to variable azimuth positions with respectto the angular position reference. The variable azimuth positionsrepresentative of prospective azimuth positions of the mobile station inrelation to the angular position reference. The first antenna azimuthgain parameter characteristic based at least in part on a first antennaposition value representative of a first azimuth position at which thefirst sector antenna is oriented in relation to the angular positionreference. In this embodiment, a second antenna elevation gain parametervalue, a second antenna maximum gain parameter value, and a secondantenna azimuth gain parameter characteristic are also retrieved fromthe storage device. The second antenna azimuth gain parametercharacteristic relating second antenna azimuth gain parameter values tothe variable azimuth positions. The second antenna azimuth gainparameter characteristic based at least in part on a second antennaposition value representative of a second azimuth position at which thesecond sector antenna is oriented in relation to the angular positionreference.

In the embodiment being described, an angular value (e.g., not exceeding360) may be selected for the variable azimuth position. The first andsecond antenna azimuth gain parameter characteristics may be used toidentify the corresponding first and second antenna azimuth gainparameter values for the variable azimuth position associated with theselected angular value. In this embodiment, the calculating in 404 maycontinue by determining a difference between first and second transmitantenna gains for the selected angular value. The difference may bedetermined by adding the first antenna azimuth gain parameter value forthe selected angular value to the first antenna elevation gain parametervalue and subtracting the first antenna maximum gain parameter value toobtain the first transmit antenna gain, adding the second antennaazimuth gain parameter value for the selected angular value to thesecond antenna elevation gain parameter value and subtracting the secondantenna maximum gain parameter value to obtain the second transmitantenna gain, and subtracting the second transmit antenna gain from thefirst transmit antenna gain to obtain a third angular positioncomponent.

The angular value selected for the initial variable azimuth position canbe based at least in part on knowledge of which sector antenna isserving the mobile station and the orientation and azimuth position ofthe serving sector antenna. Subsequent values selected for the variableazimuth position can be based on whether the subsequent result isapproaching or receding from the desired result. Various techniques canalso be used to select subsequent values for the variable azimuthposition based on the magnitude of the difference between the subsequentresult and the desired result as well as the change in the differencebetween consecutive subsequent results and the desired result.

For example, in a further embodiment of the process 400, the angularvalue initially selected for the variable azimuth position may bebetween the first and second antenna position values. In thisembodiment, the initial angular value may be representative of amid-point between the first and second antenna position values. In otherwords, if the first antenna is oriented to 120 degrees in relation tothe angular reference position, a second antenna may be oriented to 240degrees, and 180 may be selected as the initial angular value for thevariable azimuth position because it is at a midpoint between the firstand second sector antennas. The selection of other angular values forthe variable azimuth position can take into account whether the resultsare getting better or worse to select angular values to obtain betterresults. The iterative selection of angular values can be incremental orbased on a factor of the difference between the obtained result and thedesired result.

In still another further embodiment of the process 400, the calculatingin 404 also includes adding the first and third angular positioncomponents and subtracting the second angular position component to forman arithmetic result. In the embodiment being described, the arithmeticresult is converted to an absolute value. In this embodiment, if theabsolute value is within a predetermined threshold of a desired value(e.g., zero), the process 400 continues by identifying the angular valuesubstituted for the variable azimuth position as the current angularposition for the mobile station. Otherwise, the process 400 repeats theselecting with a different angular value, repeats the determining of thedifference between the first and second transmit gains to obtain a newvalue for the third angular position component, repeats the adding andsubtracting to form the arithmetic result and the determining of theabsolute value, and continues the repeating until the absolute value iswithin the predetermined threshold of the desired value.

In still yet another further embodiment of the process 400, thecalculating in 404 also includes adding the first and third angularposition components and subtracting the second angular positioncomponent to form an arithmetic result. In this embodiment, thearithmetic result is converted to an absolute value. In the embodimentbeing described, the process 400 repeats the selecting with a differentangular value, repeats the determining of the difference between thefirst and second transmit gains to obtain a new value for the thirdangular position component, repeats the adding and subtracting to formthe arithmetic result and the determining of the absolute value, andcontinues the repeating until the absolute value is minimized. In thisembodiment, the process 400 continues by identifying the correspondingangular value substituted for the variable azimuth position for whichthe absolute value is minimized as the current angular position for themobile station.

In another further embodiment of the process 400, the calculating in 404includes summing the first and third angular position components to forman arithmetic result and comparing the arithmetic result to the secondangular position component. In this embodiment, if the arithmetic resultis within a predetermined range of the second angular positioncomponent, the process 400 continues by identifying the angular valuesubstituted for the variable azimuth position as the current angularposition for the mobile station. Otherwise, the process 400 repeats theselecting with a different angular value, repeats the determining of thedifference between the first and second transmit gains to obtain a newvalue for the third angular position component, repeats the summing ofthe first and third angular position components to form the arithmeticresult and the comparing of the arithmetic result to the second angularposition component, and continues the repeating until the arithmeticresult is within the predetermined range of the second angular positioncomponent.

With reference to FIG. 6, an exemplary embodiment of an apparatus forestimating a geographic location of a mobile station 600 within acoverage area of a wireless network 602 includes a distance module 604and an angular position module 606. The distance module 604 determines aradial distance of the mobile station 600 from a base station 608serving the mobile station 600. The base station 608 includes multiplesector antennas (e.g., 610, 612, 614). The radial distance is based atleast in part on a round trip measurement associated with elapsed timebetween sending an outgoing signal from the base station 608 to themobile station 600 and receiving a corresponding acknowledgement signalfrom the mobile station 600 at the base station 608. The angularposition module 606 is in operative communication with the distancemodule 604 and calculates a current angular position of the mobilestation 600 in relation to the radial distance from the serving basestation 608. The current angular position is based at least in part on afirst signal strength measurement, a second signal strength measurement,and an angular position reference that extends outward from the servingbase station 608. The first and second signal strength measurementsrepresentative of power characteristics of respective RF signalsreceived by the mobile station 600 from corresponding first and secondsector antennas 610, 612 of the serving base station 608. The currentangular position may also be based on additional signal strengthmeasurements from other sector antennas 614 (e.g., sector antenna N).

In this embodiment, the apparatus may also include a location module 616in operative communication with the distance module 604 and angularposition module 606 for identifying a current geographic location of themobile station 600 in a coverage area of the wireless network 602 in ageographic notation based at least in part on combining the radialdistance and current angular position of the mobile station 600 relativeto the serving base station 608. In one embodiment, the radial distanceand current angular position reflect a polar coordinate-type ofgeographic notation in reference to the serving base station. In otherembodiments, the radial distance and current angular position can beconverted into various types of geographic notation, such as alatitude/longitude notation, an address notation, or a geo-bin tile gridnotation associated with the coverage area for the wireless network.

In the embodiment being described, the apparatus may also include anoutput module 618 in operative communication with the location module616 for sending the current geographic location of the mobile station600 in the geographic notation to a geo-location storage node 620associated with the wireless network 602. The geo-location storage node620 may be internal or external to the wireless network 602. In thisembodiment, the apparatus may include the serving base station 608. Inthis embodiment, the serving base station 608 may include the distancemodule 604, angular position module 606, location module 616, and outputmodule 618.

With reference to FIG. 7, an exemplary embodiment of an apparatus forestimating a geographic location of a mobile station 700 within acoverage area of a wireless network 702 includes a distance module 704and an angular position module 706. The distance module 704 determines aradial distance of the mobile station 700 from a base station 708serving the mobile station 700. The radial distance is based at least inpart on a round trip measurement associated with elapsed time betweensending an outgoing signal from the base station 708 to the mobilestation 700 and receiving a corresponding acknowledgement signal fromthe mobile station 700 at the base station 708. The angular positionmodule 706 is in operative communication with the distance module 704and calculates a current angular position of the mobile station 700 inrelation to the radial distance from the serving base station 708. Thecurrent angular position is based at least in part on a first signalstrength measurement, a second signal strength measurement, and anangular position reference that extends outward from the serving basestation 708. The first and second signal strength measurementsrepresentative of power characteristics of respective RF signalsreceived by the mobile station 700 from corresponding first and secondsector antennas 710, 712 of the serving base station 708. The currentangular position may also be based on additional signal strengthmeasurements from other sector antennas 714 (e.g., sector antenna N).

In this embodiment, the apparatus may also include a location module 716in operative communication with the distance module 704 and angularposition module 706 for identifying a current geographic location of themobile station 700 in a coverage area of the wireless network 702 in ageographic notation based at least in part on combining the radialdistance and current angular position of the mobile station 700 relativeto the serving base station 708.

In the embodiment being described, the apparatus may include ageo-location service node 722 associated with the wireless network 702and in operative communication with the serving base station 708. Inthis embodiment, the geo-location service node 722 may include thedistance module 704, angular position module 706, and location module716.

The geo-location service node 722 may also include an input module 724and an output module 718. The input module 724 in operativecommunication with the distance module 704 and angular position module706 for receiving the round trip measurement, first signal strengthmeasurement, and second signal strength measurement from the servingbase station 708 via the wireless network 702. The output module 718 inoperative communication with the location module 716 for sending thecurrent geographic location of the mobile station 700 in the geographicnotation to a geo-location storage device 726 associated with thegeo-location service node 722. The geo-location storage device 726 maybe internal or external to the geo-location service node 722. If thegeo-location storage device 726 is external to the geo-location servicenode 722, the geo-location storage device 726 may be internal orexternal to the wireless network 702.

With reference to FIG. 8, an exemplary embodiment of an apparatus forestimating a geographic location of a mobile station 800 within acoverage area of a wireless network 802 includes a distance module 804and an angular position module 806. The distance module 804 determines aradial distance of the mobile station 800 from a base station 808serving the mobile station 800. The radial distance is based at least inpart on a round trip measurement associated with elapsed time betweensending an outgoing signal from the base station 808 to the mobilestation 800 and receiving a corresponding acknowledgement signal fromthe mobile station 800 at the base station 808. The angular positionmodule 806 is in operative communication with the distance module 804and calculates a current angular position of the mobile station 800 inrelation to the radial distance from the serving base station 808. Thecurrent angular position is based at least in part on a first signalstrength measurement, a second signal strength measurement, and anangular position reference that extends outward from the serving basestation 808. The first and second signal strength measurementsrepresentative of power characteristics of respective RF signalsreceived by the mobile station 800 from corresponding first and secondsector antennas 810, 812 of the serving base station 808. The currentangular position may also be based on additional signal strengthmeasurements from other sector antennas 814 (e.g., sector antenna N).

In this embodiment, the apparatus may also include a location module 816in operative communication with the distance module 804 and angularposition module 806 for identifying a current geographic location of themobile station 800 in a coverage area of the wireless network 802 in ageographic notation based at least in part on combining the radialdistance and current angular position of the mobile station 800 relativeto the serving base station 808.

In the embodiment being described, the apparatus may include a networkmanagement node 828 associated with the wireless network 802 and inoperative communication with the serving base station 808. In thisembodiment, the network management node 828 may include the distancemodule 804, angular position module 806, and location module 816.

The network management node 828 may also include an input module 824, ameasurements storage device 830, and an output module 818. The inputmodule 824 for receiving the round trip measurement, first signalstrength measurement, and second signal strength measurement from theserving base station 808 via the wireless network 802. The measurementsstorage device 830 in operative communication with the input module 824,distance module 804, and angular position module 806 for storing theround trip measurement, first signal strength measurement, and secondsignal strength measurement. In this embodiment, the distance module 804retrieves the round trip measurement from the measurements storagedevice 830 in conjunction with determining the radial distance.Similarly, the angular position module 806 retrieves the first andsecond signal strength measurements from the measurements storage device830 in conjunction with calculating the current angular position. Theoutput module 818 in operative communication with the location module816 for sending the current geographic location of the mobile station800 in the geographic notation to the geo-location storage device 826.The geo-location storage device 826 may be internal or external to thenetwork management node 828. If the geo-location storage device 826 isexternal to the network management node 828, the geo-location storagedevice 826 may be internal or external to the wireless network 802.

With reference to FIG. 9, an exemplary embodiment of an angular positionmodule 906 associated with the apparatus of FIGS. 6-8 may include asource data communication sub-module 932 and a first angular componentsub-module 938. The source data communication sub-module 932 forretrieving first and second transmit parameter values from a storagedevice 936 associated with the wireless network. The first and secondtransmit parameter values representative of power characteristics ofrespective communication signals to be transmitted by the correspondingfirst and second sector antennas (e.g., 610, 612). In this embodiment,the first angular component sub-module 938 is in operative communicationwith the source data communication module 932 for determining adifference between the first and second transmit parameter values toobtain a first angular position component.

In a further embodiment of the angular position module 906, the sourcedata communication module may retrieve the first and second signalstrength measurements from the storage device 936. In this embodiment,the angular position module 906 may also include a second angularcomponent module 940 in operative communication with the source datacommunication module 932 for determining a difference between the firstand second signal strength measurements to obtain a second angularposition component.

In a yet further embodiment of the angular position module 906, thesource data communication sub-module 932 may also retrieve a firstantenna elevation gain parameter value, a first antenna maximum gainparameter value, and a first antenna azimuth gain parametercharacteristic from the storage device 936. The first antenna azimuthgain parameter characteristic relating first antenna azimuth gainparameter values to variable azimuth positions with respect to theangular position reference. The variable azimuth positionsrepresentative of prospective azimuth positions of the mobile station900 in relation to the angular position reference. The first antennaazimuth gain parameter characteristic based at least in part on a firstantenna position value representative of a first azimuth position atwhich the first sector antenna 910 is oriented in relation to theangular position reference.

In this embodiment, the source data communication sub-module 932 mayalso retrieve a second antenna elevation gain parameter value, a secondantenna maximum gain parameter value, and a second antenna azimuth gainparameter characteristic from the storage device 936. The second antennaazimuth gain parameter characteristic relating second antenna azimuthgain parameter values to the variable azimuth positions. The secondantenna azimuth gain parameter characteristic based at least in part ona second antenna position value representative of a second azimuthposition at which the second sector antenna 912 is oriented in relationto the angular position reference.

In the embodiment being described, the angular position module 906 mayalso include a third angular component sub-module 934 in operativecommunication with the source data communication sub-module 932. Thethird angular component sub-module 934 for selecting an angular value(e.g., not exceeding 360) for the variable azimuth position. The thirdangular component sub-module 934 using the first and second antennaazimuth gain parameter characteristics to identify the correspondingfirst and second antenna azimuth gain parameter values for the variableazimuth position associated with the selected angular value.

In this embodiment, the third angular component sub-module 934 may alsodetermine a difference between first and second transmit antenna gainsfor the selected angular value. The difference may be determined byadding the first antenna azimuth gain parameter value for the selectedangular value to the first antenna elevation gain parameter value andsubtracting the first antenna maximum gain parameter value to obtain thefirst transmit antenna gain, adding the second antenna azimuth gainparameter value for the selected angular value to the second antennaelevation gain parameter value and subtracting the second antennamaximum gain parameter value to obtain the second transmit antenna gain,and subtracting the second transmit antenna gain from the first transmitantenna gain to obtain a third angular position component.

The angular value selected for the initial variable azimuth position canbe based at least in part on knowledge of which sector antenna isserving the mobile station and the orientation and azimuth position ofthe serving sector antenna. Subsequent values selected for the variableazimuth position can be based on whether the subsequent result isapproaching or receding from the desired result. Various techniques canalso be used to select subsequent values for the variable azimuthposition based on the magnitude of the difference between the subsequentresult and the desired result as well as the change in the differencebetween consecutive subsequent results and the desired result.

For example, in a further embodiment of the angular position module 906,the angular value initially selected for the variable azimuth positionby the third angular component sub-module 934 may be between the firstand second antenna position values. In this embodiment, the initialangular value may be representative of a mid-point between the first andsecond antenna position values. In other words, if the first antenna isoriented to 120 degrees in relation to the angular reference position, asecond antenna may be oriented to 240 degrees, and 180 may be selectedas the initial angular value for the variable azimuth position becauseit is at a midpoint between the first and second sector antennas. Theselection of other angular values for the variable azimuth position cantake into account whether the results are getting better or worse toselect angular values to obtain better results. The iterative selectionof angular values can be incremental or based on a factor of thedifference between the obtained result and the desired result.

In a yet further embodiment, the angular position module 906 may includean arithmetic sub-module 942 and a control sub-module 944. In thisembodiment, the arithmetic sub-module 942 is in operative communicationwith the first, second, and third angular component modules 938, 940,934 for adding the first and third angular position components andsubtracting the second angular position component to form an arithmeticresult. In the embodiment being described, the arithmetic sub-module 942converts the arithmetic result to an absolute value. The controlsub-module 944 is in operative communication with the arithmeticsub-module 942 and the third angular component sub-module 934 foridentifying the angular value substituted for the variable azimuthposition as the current angular position for the mobile station 900 ifthe arithmetic result is within a predetermined threshold of a desiredvalue (e.g., zero). Otherwise, the control sub-module 944 may causes thethird angular component module 934 to repeat the selecting with adifferent angular value and the determining of the difference betweenthe first and second transmit gains to obtain a new value for the thirdangular position component, causes the arithmetic sub-module 942 torepeat the adding and subtracting to form the arithmetic result and thedetermining of the absolute value, and causes the repeating to continueuntil the arithmetic result is within the predetermined threshold of thedesired value.

In an alternate further embodiment, the arithmetic sub-module 942 may bein operative communication with the first, second, and third angularcomponent modules 938, 940, 934 for adding the first and third angularposition components and subtracting the second angular positioncomponent to form an arithmetic result. In the embodiment beingdescribed, the arithmetic sub-module 942 converts the arithmetic resultto an absolute value. In this embodiment, the control sub-module 944 maybe in operative communication with the arithmetic sub-module 942 and thethird angular component module 934 for causing the third angularcomponent sub-module 934 to repeat the selecting with a differentangular value and the determining of the difference between the firstand second transmit gains to obtain a new value for the third angularposition component, causing the arithmetic sub-module 942 to repeat theadding and subtracting to form the arithmetic result and the determiningof the absolute value, and causing the repeating to continue until theabsolute value is minimized. In the embodiment being described, thecontrol sub-module 944 identifies the corresponding angular valuesubstituted for the variable azimuth position for which the absolutevalue is minimized as the current angular position for the mobilestation 900.

In another alternate further embodiment, the arithmetic sub-module 942may be in operative communication with the first, second, and thirdangular component modules 938, 940, 934 for summing the first and thirdangular position components to form an arithmetic result. In theembodiment being described, the arithmetic sub-module 942 compares thearithmetic result to the second angular position component 940. In thisembodiment, the control sub-module 944 may be in operative communicationwith the arithmetic sub-module 942 and the third angular componentsub-module 934 for identifying the angular value substituted for thevariable azimuth position as the current angular position for the mobilestation if the arithmetic result is within a predetermined range of thesecond angular position component. Otherwise, the control sub-module 944causes the third angular component module 934 to repeat the selectingwith a different angular value and the determining of the differencebetween the first and second transmit gains to obtain a new value forthe third angular position component, causes the arithmetic sub-module942 to repeat the summing of the first and third angular positioncomponents to form the arithmetic result and the comparing of thearithmetic result to the second angular position component, and causethe repeating to continue until the arithmetic result is within thepredetermined range of the second angular position component.

With reference to FIG. 10, an exemplary embodiment of a non-transitorycomputer-readable medium storing program instructions that, whenexecuted by a computer, cause a corresponding computer-controlled deviceto perform a process 1000 for estimating a geographic location of amobile station within a coverage area of a wireless network. In oneembodiment, the process 1000 begins at 1002 where a radial distance of amobile station from a base station is calculated. The base stationincluding multiple sector antennas. The radial distance is based atleast in part on a round trip measurement associated with elapsed timebetween sending an outgoing signal from the base station to the mobilestation and receiving a corresponding acknowledgement signal from themobile station at the base station. At 1004, the process determines asignal strength report from the mobile station provided to the basestation includes a signal strength measurement representative of a powercharacteristic of an RF signal received by the mobile station from asector antenna of the base station. Next, an instant geographic locationof the mobile station in a coverage area of the wireless network may beidentified (1006).

In various embodiments, the program instructions stored in thenon-transitory computer-readable memory, when executed by the computer,may cause the computer-controlled device to perform various combinationsof functions associated with the various embodiments of the processes400, 500, 1700, 1800, 1900, 2000, 2100, 2200, and 2300 for estimating ageographic location of a mobile station described above with referenceto FIGS. 4, 5, and 17-23. In other words, the various embodiments of theprocesses 400, 500, 1700, 1800, 1900, 2000, 2100, 2200, and 2300described above may also be implemented by corresponding embodiments ofthe process 1000 associated with the program instructions stored in thenon-transitory computer-readable memory.

Likewise, in various embodiments, the program instructions stored in thenon-transitory computer-readable memory, when executed by the computer,may cause the computer-controlled device to perform various combinationsof functions associated with the various embodiments of the apparatusfor estimating a geographic location of a mobile station described abovewith reference to FIGS. 6-8 and the angular position module 906described above with reference to FIG. 9.

For example, the computer-controlled device may include a base station(see FIG. 6, 608), a geo-location service node (see FIG. 7, 722), anetwork management node (see FIG. 8, 828), or any suitable communicationnode associated with the wireless network. Any suitable module orsub-module described above with reference to FIGS. 6-9 may include thecomputer and non-transitory computer-readable memory associated with theprogram instructions. Alternatively, the computer and non-transitorycomputer-readable memory associated with the program instructions may beindividual or combined components that are in operative communicationwith any suitable combination of the modules and sub-modules describedabove with reference to FIGS. 6-9

The above description merely provides a disclosure of particularembodiments of the invention and is not intended for the purposes oflimiting the same thereto. As such, the invention is not limited to onlythe above-described embodiments. Rather, it is recognized that oneskilled in the art could conceive alternative embodiments that fallwithin the scope of the invention.

We claim:
 1. A method for mapping an operating parameter in a coveragearea of a wireless network, comprising: at a network management node,obtaining parameter measurements for a select operating parameterassociated with one or more mobile stations operating in at least aselect portion of a network coverage area for a wireless network, theparameter measurements having been measured during a select calendartimeframe, the network coverage area formed by a plurality of basestations, each base station defining a cellular coverage area within thenetwork coverage area, the select portion of the network coverage areaformed by at least one base station, each at least one base stationincluding multiple sector antennas, each sector antenna defining asector coverage area within the cellular coverage area for thecorresponding base station, wherein the network management node isassociated with the wireless network; and for each obtained parametermeasurement, estimating an instant geographic location of thecorresponding mobile station in relation to the at least one basestation serving the corresponding mobile station, each instantgeographic location based at least in part on a round trip measurementand at least one signal strength measurement associated with thecorresponding mobile station, each round trip measurement associatedwith the at least one base station serving the corresponding mobilestation, each round trip measurement and corresponding at least onesignal strength measurement related in calendar time to thecorresponding parameter measurement.
 2. The method of claim 1, furthercomprising: processing the obtained parameter measurements for eachinstant geographic location to obtain a representative parameter valuefor the corresponding instant geographic location; and populating acoverage area map for the wireless network with the representativeparameter values based at least in part on the instant geographiclocation associated with the corresponding representative parametervalue, the coverage area map including at least the select portion ofthe network coverage area.
 3. The method of claim 2 wherein therepresentative parameter values are obtained by one or more of filteringthe corresponding parameter measurements to remove unreliablemeasurements, averaging the corresponding parameter measurements,determining a median value for the corresponding parameter measurements,and selecting a preferred parameter measurement from the correspondingparameter measurements based at least in part on a preferred calendartime for the corresponding representative parameter value.
 4. The methodof claim 2 wherein the coverage area map is a radio frequency (RF)coverage area map, a handoff zone coverage area map, a data usagecoverage area map, a signaling usage coverage area map, a populationcoverage area map for directory number identification, deviceidentification, device type, or application program, a quality ofservice coverage area map for throughput, packet loss, or packet delay,or a user profile coverage area map.
 5. The method of claim 1 wherein atleast the select portion of the network coverage area is represented ina coverage area map for the wireless network by a plurality ofsub-sector geographic areas, each sub-sector geographic area uniquelyidentified and associated with at least a portion of the sector coveragearea for at least one sector antenna, the method further comprising:correlating each estimated instant geographic location with a sub-sectorgeographic area of the plurality of sub-sector geographic areas, eachsub-sector geographic area adapted to represent more than one instantgeographic location, the correlating based at least in part on areference location in the coverage area map for the at least one basestation serving the mobile station associated with the correspondinginstant geographic location.
 6. The method of claim 5, furthercomprising: processing the obtained parameter measurements for eachsub-sector geographic area to obtain a representative parameter valuefor the corresponding sub-sector geographic area; and populating thecoverage area map with the representative parameter values based atleast in part on the sub-sector geographic area associated with thecorresponding representative parameter value.
 7. The method of claim 5wherein each sub-sector geographic area is associated with acorresponding geographic location bin for storage of parametermeasurements associated with the instant geographic locationsrepresented by the corresponding sub-sector geographic, the methodfurther comprising: storing each obtained parameter measurement in ageographic location bin associated with the sub-sector geographic arearepresenting the instant geographic location associated with thecorresponding parameter measurement; processing the parametermeasurements stored in each geographic location bin to obtain arepresentative parameter value for the corresponding geographic locationbin; and populating the coverage area map with the representativeparameter values based at least in part on the geographic location binassociated with the corresponding representative parameter value and thesub-sector geographic area associated with the corresponding geographiclocation bin.
 8. The method of claim 1 wherein the parametermeasurements are obtained from call records, subscriber records, andservice provider records captured or maintained during normal operationof the wireless network that provide wireless services to mobilestations or that support accounting and billing functions for theservice provider.
 9. The method of claim 1 wherein the select operatingparameter includes one or more of a signal strength parameter associatedwith radio frequency (RF) signals received by mobile stations fromsector antennas, a handoff parameter associated with handoffs of mobilestations from serving sector antennas to neighboring sector antennas ofserving base stations or neighboring base stations, a data usageparameter associated with data usage during call sessions to and frommobile stations, a signaling usage parameter associated with setup andteardown of call sessions to and from mobile stations, a directorynumber identification parameter associated with telephone numbers formobile stations, a device identification parameter associated withserial numbers of mobile stations, a device type parameter associatedwith categorizing mobile stations into different types by manufacturer,model, or technical feature, an application identification parameterassociated with application programs used by mobile stations, athroughput parameter associated with call sessions for mobile stations,a packet loss parameter associated with call sessions for mobilestations, a packet delay parameter associated with call sessions formobile stations, and a user profile parameter associated with observedbehavior or preferences of users of mobile stations.
 10. The method ofclaim 1 wherein the select portion of the network coverage area isformed by at least two base stations, each at least two base stationsincluding multiple sector antennas.
 11. The method of claim 1 wherein atleast some instant geographic locations are based at least in part onthe round trip measurement and first and second signal strengthmeasurements of the at least one signal strength measurement, the firstand second signal strength measurements being from different sectorantennas.
 12. The method of claim 1 wherein at least some instantgeographic locations are based at least in part on the round tripmeasurement, a first signal strength measurement of the at least onesignal strength measurement, and a first RF coverage map for a firstsector antenna serving the mobile station associated with the round tripmeasurement and with which the first signal strength measurement isassociated.
 13. The method of claim 12 wherein one or more instantgeographic locations are also based at least in part on a second signalstrength measurement of the at least one signal strength measurement anda second RF coverage map for a second sector antenna with which thesecond signal strength measurement is associated, the second sectorantenna associated with a neighboring base station in relation to thebase station serving the mobile station.
 14. The method of claim 1wherein parameter measurements are obtained and the instant geographiclocations are estimated in response to detection of a dropped call forthe one or more mobile stations.
 15. An apparatus for mapping anoperating parameter in a coverage area of a wireless network,comprising: an input module configured to obtain parameter measurementsfor a select operating parameter associated with one or more mobilestations operating in at least a select portion of a network coveragearea for a wireless network, the parameter measurements having beenmeasured during a select calendar timeframe, the network coverage areaformed by a plurality of base stations, each base station defining acellular coverage area within the network coverage area, the selectportion of the network coverage area formed by at least one basestation, each at least one base station including multiple sectorantennas, each sector antenna defining a sector coverage area within thecellular coverage area for the corresponding base station; and alocation module in operative communication with the input module andconfigured to estimate an instant geographic location of thecorresponding mobile station for each obtained parameter measurement inrelation to the at least one base station serving the correspondingmobile station, each instant geographic location based at least in parton a round trip measurement and at least one signal strength measurementassociated with the corresponding mobile station, the round trip and atleast one signal strength measurements obtained via the input module,each round trip measurement associated with the at least one basestation serving the corresponding mobile station, each round tripmeasurement and corresponding at least one signal strength measurementrelated in calendar time to the corresponding parameter measurement. 16.The apparatus of claim 15, further comprising: a processing module inoperative communication with the input module and location module andconfigured to process the obtained parameter measurements for eachinstant geographic location to obtain a representative parameter valuefor the corresponding instant geographic location; and a mapping modulein operative communication with the processing module and configured topopulate a coverage area map for the wireless network with therepresentative parameter values based at least in part on the instantgeographic location associated with the corresponding representativeparameter value, the coverage area map including at least the selectportion of the network coverage area.
 17. The apparatus of claim 15wherein at least the select portion of the network coverage area isrepresented in a coverage area map for the wireless network by aplurality of sub-sector geographic areas, each sub-sector geographicarea uniquely identified and associated with at least a portion of thesector coverage area for at least one sector antenna, the apparatusfurther comprising: a correlation module in operative communication withthe location module and configured to correlate each estimated instantgeographic location with a sub-sector geographic area of the pluralityof sub-sector geographic areas, each sub-sector geographic area adaptedto represent more than one instant geographic location, the correlatingbased at least in part on a reference location in the coverage area mapfor the at least one base station serving the mobile station associatedwith the corresponding instant geographic location.
 18. The apparatus ofclaim 17, further comprising: a processing module in operativecommunication with the input module and correlating module andconfigured to process the obtained parameter measurements for eachsub-sector geographic area to obtain a representative parameter valuefor the corresponding sub-sector geographic area; and a mapping modulein operative communication with the processing module and configured topopulate the coverage area map with the representative parameter valuesbased at least in part on the sub-sector geographic area associated withthe corresponding representative parameter value.
 19. The apparatus ofclaim 17 wherein each sub-sector geographic area is associated with acorresponding geographic location bin for storage of parametermeasurements associated with the instant geographic locationsrepresented by the corresponding sub-sector geographic, the apparatusfurther comprising: a storage device in operative communication with theinput module and the location module and configured to store eachobtained parameter measurement in a geographic location bin associatedwith the sub-sector geographic area representing the instant geographiclocation associated with the corresponding parameter measurement,wherein the storage device also stores the round trip and signalstrength measurements used by the location module; a processing modulein operative communication with the storage device and correlatingmodule and configured to process the parameter measurements stored ineach geographic location bin to obtain a representative parameter valuefor the corresponding geographic location bin; and a mapping module inoperative communication with the processing module and configured topopulate the coverage area map with the representative parameter valuesbased at least in part on the geographic location bin associated withthe corresponding representative parameter value and the sub-sectorgeographic area associated with the corresponding geographic locationbin.
 20. A non-transitory computer-readable medium storing programinstructions that, when executed by a computer, cause a correspondingcomputer-controlled device to perform a method for mapping an operatingparameter in a coverage area of a wireless network, the methodcomprising: obtaining parameter measurements for a select operatingparameter associated with one or more mobile stations operating in atleast a select portion of a network coverage area for a wirelessnetwork, the parameter measurements having been measured during a selectcalendar timeframe, the network coverage area formed by a plurality ofbase stations, each base station defining a cellular coverage areawithin the network coverage area, the select portion of the networkcoverage area formed by at least one base station, each at least onebase station including multiple sector antennas, each sector antennadefining a sector coverage area within the cellular coverage area forthe corresponding base station; and for each obtained parametermeasurement, estimating an instant geographic location of thecorresponding mobile station in relation to the at least one basestation serving the corresponding mobile station, each instantgeographic location based at least in part on a round trip measurementand at least one signal strength measurement associated with thecorresponding mobile station, each round trip measurement associatedwith the at least one base station serving the corresponding mobilestation, each round trip measurement and corresponding at least onesignal strength measurement related in calendar time to thecorresponding parameter measurement.
 21. The non-transitorycomputer-readable medium of claim 20, the method further comprising:processing the obtained parameter measurements for each instantgeographic location to obtain a representative parameter value for thecorresponding instant geographic location; and populating a coveragearea map for the wireless network with the representative parametervalues based at least in part on the instant geographic locationassociated with the corresponding representative parameter value, thecoverage area map including at least the select portion of the networkcoverage area.
 22. The non-transitory computer-readable medium of claim20 wherein at least the select portion of the network coverage area isrepresented in a coverage area map for the wireless network by aplurality of sub-sector geographic areas, each sub-sector geographicarea uniquely identified and associated with at least a portion of thesector coverage area for at least one sector antenna, the method furthercomprising: correlating each estimated instant geographic location witha sub-sector geographic area of the plurality of sub-sector geographicareas, each sub-sector geographic area adapted to represent more thanone instant geographic location, the correlating based at least in parton a reference location in the coverage area map for the at least onebase station serving the mobile station associated with thecorresponding instant geographic location.
 23. The non-transitorycomputer-readable medium of claim 22, the method further comprising:processing the obtained parameter measurements for each sub-sectorgeographic area to obtain a representative parameter value for thecorresponding sub-sector geographic area; and populating the coveragearea map with the representative parameter values based at least in parton the sub-sector geographic area associated with the correspondingrepresentative parameter value.
 24. The non-transitory computer-readablemedium of claim 22 wherein each sub-sector geographic area is associatedwith a corresponding geographic location bin for storage of parametermeasurements associated with the instant geographic locationsrepresented by the corresponding sub-sector geographic, the methodfurther comprising: storing each obtained parameter measurement in ageographic location bin associated with the sub-sector geographic arearepresenting the instant geographic location associated with thecorresponding parameter measurement; processing the parametermeasurements stored in each geographic location bin to obtain arepresentative parameter value for the corresponding geographic locationbin; and populating the coverage area map with the representativeparameter values based at least in part on the geographic location binassociated with the corresponding representative parameter value and thesub-sector geographic area associated with the corresponding geographiclocation bin.